ui: view for go env and important settings that affects go's functionality

[hyangah]

There are dozens of settings and environment variables affecting how go command works.
go env or commands to inspect environment variables is a typical way to inspect them,
but often the environment the extension (or vscode extension host) is different from what
users see from their terminals (e.g. users use shell config that does not get invoked when
vscode launches, etc.). That causes confusions numerous times.

We added some of the info in the Go: Locate Configured Tools command output, but
the output is verbose and text-heavy. It's time to think about better UI. An option is View.

Info to included in the new Go Env view

• go env output
  • GOWORK (related to ui: make go.work value visible #2032)
  • GOMOD
  • GOOS
  • GOARCH
  • GOENV
  • GOFLAGS
  • GOPRIVATE
  • GOBIN
  • GOPATH
  • GOROOT
    ...
• Path to the go command (or GOROOT)
• List of tools
  • Name, path, version
• settings affecting build/test (e.g. go.buildFlags, or tags)

Future work

This view may be extended in the future to have associated commands

• to open the associated resources (e.g. open go.mod file)
• to trigger setting changes (e.g. Allow setting GOOS via UI)
• to update tools

Remarks

• The info in the view may need to change depending on the workspace root folder the open file belongs to.

• I cannot think of a good existing default container (explorer/scm/debug/test) where this new view belongs to yet. We may need to create a custom view container for Go - where we can organize more go-project specific information (Module/Package dependencies, Package doc, ...)

cc @jamalc @golang/tools-team

[hyangah]

Of course, this is not the first time I thought about this :-) #1630

[gopherbot]

Change https://go.dev/cl/388754 mentions this issue: src/goExplorer.ts: display tools configuration detail in explorer view

[gopherbot]

Change https://go.dev/cl/388435 mentions this issue: src/goExplorer.ts: add a go tree view to the explorer

[gopherbot]

Change https://go.dev/cl/389454 mentions this issue: test/integration: test go explorer tree view ui

[gopherbot]

Change https://go.dev/cl/391254 mentions this issue: package.json: add go icon to explorer view

[gopherbot]

Change https://go.dev/cl/391255 mentions this issue: src/goExplorer.ts: consolidate tools information into single tree item

[gopherbot]

Change https://go.dev/cl/391256 mentions this issue: src/goExplorer.ts: create opened files if they do not exist

[gopherbot]

Change https://go.dev/cl/391515 mentions this issue: src/goExplorer.ts: make workspace go env editable via commands

[hyangah]

From v0.33.0, there will be a Go view in the Explorer container by default and that will present some environment variables and tool locations and versions. We plan to extend this to provide easy access to update the env vars or flag variables in the future. Users can move the view to the activity bar directly, move to bottom of the editor, or completely hide it like other views.

Thanks @jamalc

[polinasok]

Should go.toolsEnvVars settings be reflected as well? That could help with highlighting hidden settings like in #2206.
Or maybe settings.json could be its own separate Explorer category. And another launch.json section when debug session is running could be nice too.