fix(schema): use editor for rendering schema export instead of LG code for performance COMPASS-8980

[Anemy]

COMPASS-8980
LeafyGreen's Code component gets laggy when given a large document (mostly from computing the dom highlighting). The exported schema json can get large, especially in the Extended format. This PR updates the export schema modal copyable output to be a code mirror read only editor. It renders it virtually and makes it a lot quicker to render.

Quick speed benchmarks on my machine, all collections are in Compass Data Sets, tested with the Extended format:

namespace	render time before (ms)	render time after (ms)
NYC.buildings	2616	65
NYC.trees	1979	50
sample_airbnb.lightingsAndReviews	15228	279

before	after

^ There's a copy button on the after if the user hovers over it.

[gribnoysup]

Small question, otherwise looks good

[paula-stacho]

🎉