fix: correctly cache expensive operation

[pauldambra]

cssText mutates so shouldn't be the cache key...
we store it before mutating

follow-up to #17

[github-actions]

Size Change: +220 B (0%)

Total Size: 10.3 MB

Filename	Size	Change
packages/all/dist/rrweb-all.cjs	555 kB	+17 B (0%)
packages/all/dist/rrweb-all.js	555 kB	+17 B (0%)
packages/all/dist/rrweb-all.umd.cjs	559 kB	+17 B (0%)
packages/all/dist/rrweb-all.umd.min.cjs	272 kB	+4 B (0%)
packages/record/dist/rrweb-record.cjs	377 kB	+17 B (0%)
packages/record/dist/rrweb-record.js	377 kB	+17 B (0%)
packages/record/dist/rrweb-record.umd.cjs	380 kB	+17 B (0%)
packages/record/dist/rrweb-record.umd.min.cjs	182 kB	+4 B (0%)
packages/rrweb-snapshot/dist/rrweb-snapshot.cjs	163 kB	+17 B (+0.01%)
packages/rrweb-snapshot/dist/rrweb-snapshot.js	162 kB	+17 B (+0.01%)
packages/rrweb-snapshot/dist/rrweb-snapshot.umd.cjs	166 kB	+17 B (+0.01%)
packages/rrweb-snapshot/dist/rrweb-snapshot.umd.min.cjs	81.6 kB	+4 B (0%)
packages/rrweb/dist/rrweb.cjs	538 kB	+17 B (0%)
packages/rrweb/dist/rrweb.js	538 kB	+17 B (0%)
packages/rrweb/dist/rrweb.umd.cjs	539 kB	+17 B (0%)
packages/rrweb/dist/rrweb.umd.min.cjs	262 kB	+4 B (0%)

ℹ️ View Unchanged

Filename	Size
packages/packer/dist/base-B40z8PPs.cjs	18.3 kB
packages/packer/dist/base-B40z8PPs.umd.cjs	19.4 kB
packages/packer/dist/base-B40z8PPs.umd.min.cjs	10.1 kB
packages/packer/dist/base-BrE4jft0.js	18.2 kB
packages/packer/dist/pack.cjs	347 B
packages/packer/dist/pack.js	285 B
packages/packer/dist/pack.umd.cjs	2.25 kB
packages/packer/dist/pack.umd.min.cjs	1.73 kB
packages/packer/dist/packer.cjs	257 B
packages/packer/dist/packer.js	136 B
packages/packer/dist/packer.umd.cjs	1.28 kB
packages/packer/dist/packer.umd.min.cjs	1.25 kB
packages/packer/dist/unpack.cjs	769 B
packages/packer/dist/unpack.js	702 B
packages/packer/dist/unpack.umd.cjs	1.79 kB
packages/packer/dist/unpack.umd.min.cjs	1.57 kB
packages/plugins/rrweb-plugin-canvas-webrtc-record/dist/rrweb-plugin-canvas-webrtc-record.cjs	37.6 kB
packages/plugins/rrweb-plugin-canvas-webrtc-record/dist/rrweb-plugin-canvas-webrtc-record.js	37.5 kB
packages/plugins/rrweb-plugin-canvas-webrtc-record/dist/rrweb-plugin-canvas-webrtc-record.umd.cjs	38.7 kB
packages/plugins/rrweb-plugin-canvas-webrtc-record/dist/rrweb-plugin-canvas-webrtc-record.umd.min.cjs	22.9 kB
packages/plugins/rrweb-plugin-canvas-webrtc-replay/dist/rrweb-plugin-canvas-webrtc-replay.cjs	34.3 kB
packages/plugins/rrweb-plugin-canvas-webrtc-replay/dist/rrweb-plugin-canvas-webrtc-replay.js	34.2 kB
packages/plugins/rrweb-plugin-canvas-webrtc-replay/dist/rrweb-plugin-canvas-webrtc-replay.umd.cjs	35.4 kB
packages/plugins/rrweb-plugin-canvas-webrtc-replay/dist/rrweb-plugin-canvas-webrtc-replay.umd.min.cjs	21.2 kB
packages/plugins/rrweb-plugin-console-record/dist/rrweb-plugin-console-record.cjs	15 kB
packages/plugins/rrweb-plugin-console-record/dist/rrweb-plugin-console-record.js	14.9 kB
packages/plugins/rrweb-plugin-console-record/dist/rrweb-plugin-console-record.umd.cjs	16.1 kB
packages/plugins/rrweb-plugin-console-record/dist/rrweb-plugin-console-record.umd.min.cjs	8.03 kB
packages/plugins/rrweb-plugin-console-replay/dist/rrweb-plugin-console-replay.cjs	5.01 kB
packages/plugins/rrweb-plugin-console-replay/dist/rrweb-plugin-console-replay.js	4.9 kB
packages/plugins/rrweb-plugin-console-replay/dist/rrweb-plugin-console-replay.umd.cjs	6.07 kB
packages/plugins/rrweb-plugin-console-replay/dist/rrweb-plugin-console-replay.umd.min.cjs	3.27 kB
packages/plugins/rrweb-plugin-sequential-id-record/dist/rrweb-plugin-sequential-id-record.cjs	681 B
packages/plugins/rrweb-plugin-sequential-id-record/dist/rrweb-plugin-sequential-id-record.js	548 B
packages/plugins/rrweb-plugin-sequential-id-record/dist/rrweb-plugin-sequential-id-record.umd.cjs	1.76 kB
packages/plugins/rrweb-plugin-sequential-id-record/dist/rrweb-plugin-sequential-id-record.umd.min.cjs	1.47 kB
packages/plugins/rrweb-plugin-sequential-id-replay/dist/rrweb-plugin-sequential-id-replay.cjs	933 B
packages/plugins/rrweb-plugin-sequential-id-replay/dist/rrweb-plugin-sequential-id-replay.js	820 B
packages/plugins/rrweb-plugin-sequential-id-replay/dist/rrweb-plugin-sequential-id-replay.umd.cjs	2.01 kB
packages/plugins/rrweb-plugin-sequential-id-replay/dist/rrweb-plugin-sequential-id-replay.umd.min.cjs	1.61 kB
packages/replay/dist/rrweb-replay.cjs	388 kB
packages/replay/dist/rrweb-replay.js	388 kB
packages/replay/dist/rrweb-replay.umd.cjs	391 kB
packages/replay/dist/rrweb-replay.umd.min.cjs	194 kB
packages/replay/dist/style.css	2.45 kB
packages/replay/dist/style.min.css	1.97 kB
packages/rrdom-nodejs/dist/rrdom-nodejs.cjs	132 kB
packages/rrdom-nodejs/dist/rrdom-nodejs.js	131 kB
packages/rrdom-nodejs/dist/rrdom-nodejs.umd.cjs	134 kB
packages/rrdom-nodejs/dist/rrdom-nodejs.umd.min.cjs	66.9 kB
packages/rrdom/dist/rrdom.cjs	150 kB
packages/rrdom/dist/rrdom.js	149 kB
packages/rrdom/dist/rrdom.umd.cjs	152 kB
packages/rrdom/dist/rrdom.umd.min.cjs	74.1 kB
packages/rrweb-player/dist/events.js	159 kB
packages/rrweb-player/dist/global.css	240 B
packages/rrweb-player/dist/rrweb-player.cjs	460 kB
packages/rrweb-player/dist/rrweb-player.js	460 kB
packages/rrweb-player/dist/rrweb-player.umd.cjs	463 kB
packages/rrweb-player/dist/rrweb-player.umd.min.cjs	223 kB
packages/rrweb-player/dist/style.css	5.57 kB
packages/rrweb-player/dist/style.min.css	5 kB
packages/rrweb/dist/style.css	2.45 kB
packages/rrweb/dist/style.min.css	1.97 kB
packages/types/dist/rrweb-types.cjs	5.64 kB
packages/types/dist/rrweb-types.js	5.38 kB
packages/types/dist/rrweb-types.umd.cjs	6.66 kB
packages/types/dist/rrweb-types.umd.min.cjs	3.42 kB
packages/utils/dist/rrweb-utils.cjs	6.07 kB
packages/utils/dist/rrweb-utils.js	5.58 kB
packages/utils/dist/rrweb-utils.umd.cjs	7.1 kB
packages/utils/dist/rrweb-utils.umd.min.cjs	3.99 kB

_{compressed-size-action}