Track language usage (via file extensions) in Gitpod

[loujaybee]

Track the language (file extension) of edited files, by firing an event with the file extension (language) when a user opens and edits. a file. We only need to fire a single event per language, per workspace, as more events are not needed.

[mustard-mh]

Close since all merged.

This event tracks user activated languages by explicitly giving a focus to an editor. If an editor is opened by IDE but a user never gives a focus to it then such document is not tracked, i.e. during file searching among many files. Each language is tracked only once per session, not for each opened document.

Documented tracking event info in notion JetBrains and VSCode.

[akosyakov]

@mustard-mh I'm reopening it.

Because @jakobhero brought that it would be cool to track all opened files. I was afraid that it will be expensive, since we don't really need to store all these events but rather count languages usages per a user. Maybe we can do it like suggested here.

Not super important though, you can work for now on graceful shutdown of IDEs and then come back to it for research.