Add v2 modules to integration tests

[doriable]

This adds v2 modules to all buf/cmd/buf workspace and lint integration tests.
It also covers a couple of a bit of clean-up around error messages.

[bufdev]

I would love some tests added to probably buflint_test.go that test the new ignore_only paths being relative to the buf.yaml instead of being root-relative, and some tests that test excludes per directory in these integration tests, does that make sense/could you add those?

[bufdev]

Also, are there any tests checking how v2 integrates with --config? I already can't remember the design decision I made regarding --config with inline v2 values, but would love us to lock in that behavior.

[doriable]

Also, are there any tests checking how v2 integrates with --config? I already can't remember the design decision I made regarding --config with inline v2 values, but would love us to lock in that behavior.

So there currently is a test that inlines v2 config with --config. It seems that the expectation right now is that it returns a non-zero status code (1) but does not provide a helpful error string.

buf/private/buf/cmd/buf/workspace_test.go

Lines 189 to 207 in 4b7b26d

	testRunStdout(
	t,
	nil,
	1,
	"",
	"lint",
	filepath.Join("testdata", "workspace", "success", baseDirPath),
	"--config",
	`version: v2
	modules:
	- directory: a
	- directory: other/proto
	lint:
	use:
	- PACKAGE_DIRECTORY_MATCH
	- directory: proto`,
	"--path",
	filepath.Join("testdata", "workspace", "success", baseDirPath, "other", "proto", "request.proto"),
	)

[bufdev]

This isnt used

[doriable]

Ah yes, I ended up going with targeting the opaque IDs instead

[bufdev]

change to:

opaqueID := moduleFullNameString
if opaqueID == "" {
  opaqueID = "."
}

[bufdev]

Why did this move?

[doriable]

Oh, I think I moved this by accident while traversing some of the helpers. Moved it back.