Handle log-viewer heartbeat

[Nadahar]

This is meant to illustrate some of what I suggested in #3569. I don't consider it complete, both because I'm not sure if what I did in ws.ts is correct/complete (no close callback implemented events, for example) and because I'm not sure if the visual solution is ideal.

I haven't attempted to make any reconnect timer mechanism either. But, it does seem to function. As a plus, it turns out that it also solves a problem I didn't know existed: The "heartbeat timer" is never stopped if the remote closes the connection. With this PR it does, so it doesn't keep trying to send the heartbeat over and over again after the socket is closed.

[relativeci]

#4082 Bundle Size — 12.54MiB (~+0.01%).

9342247(current) vs 005e8c7 main#4081(baseline)

Warning

Bundle contains 2 duplicate packages – View duplicate packages

Bundle metrics   2 changes 1 regression

	Current #4082	Baseline #4081
Initial JS	1.52MiB(~+0.01%)	1.52MiB
Initial CSS	0B	0B
Cache Invalidation	7.06%	7.05%
Chunks	620	620
Assets	702	702
Modules	2437	2437
Duplicate Modules	0	0
Duplicate Code	0%	0%
Packages	130	130
Duplicate Packages	1	1

Bundle size by type   2 changes 2 regressions

	Current #4082	Baseline #4081
JS	10.87MiB (~+0.01%)	10.87MiB
CSS	846.54KiB (+0.03%)	846.25KiB
Fonts	526.1KiB	526.1KiB
Media	295.6KiB	295.6KiB
IMG	45.73KiB	45.73KiB
Other	847B	847B

Bundle analysis report Branch Nadahar:log-viewer Project dashboard

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