Add debuggin' to the plugin

[Kira-Pilot]

Recently we have been investigating a hard-to-reproduce integrated terminal latency issue. We should introduce some logging and diagnostics into the plugin so we can provide a build to the affected user and glean more information:

• add centralized logger (if there isn't one already)
• add debug calls to thorny areas of code as identified in our walkthrough, as well as to lifecycle events
• provide user with a debug build

Logging Ideas:
https://github.com/coder/vscode-coder/blob/main/src/remote.ts#L745
Is polling continuing indefinitely here?

https://github.com/coder/vscode-coder/blob/main/src/remote.ts#L785
are repeated file reads here slowing down performance?

https://github.com/coder/coder/blob/main/cli/vscodessh.go#L33
anything weird going on in here? This is the Go code on the Coder side. We wouldn't add logging here but might consider this interface on the plugin side considering VS Code is reading from it continuously to display connection info via a callback.
https://github.com/coder/coder/blob/main/cli/vscodessh.go#L199

We might want to log memory usage over time to see if we find any jump.

[bcpeinhardt]

There is a centralized logger, and a dedicated output channel for the extension which we write to. I think a further thing we could provide is a "Support.md" file, with instructions on what debugging/troubleshooting tools we provide and how to collect information for CS. Ideally any part of that process that can be scripted should be.

[f0ssel]

Some ideas:

• Ask if they can upgrade in staging to new version that uses coder ssh over coder vscoderssh
• Investigate SSH processes on the machine when things are good vs slow
• Investigate vscode log dumps locations and coder ssh log dumps
• Possibly looking at network logs with a netgru person