x/tools/gopls: support pull-based diagnostics available in LSP 3.17

[hyangah]

LSP 3.17 adds support for Pull Diagnostics

The spec includes Document Diagnostics, Workspace Diagnostics.

I think this allows us to address some long-standing issues like

• https://github.com/golang/vscode-go/issues/50 Support a setting to control the frequency of diagnostics (some users want to see diagnostics only when they save a file, not as they type
• https://github.com/golang/vscode-go/issues/1275 Option to run diagnostics only on current package

Partly

• https://github.com/golang/go/issues/42527 Support diagnostics for files inside vendor directories
• https://github.com/golang/go/issues/45607#issuecomment-823694873 Fine-grained control on diagnostics

[gopherbot]

Change https://go.dev/cl/611843 mentions this issue: gopls/internal/cache: join concurrent package batch operations

[gopherbot]

Change https://go.dev/cl/616835 mentions this issue: gopls: add initial support for pull diagnostics

[gopherbot]

Change https://go.dev/cl/618995 mentions this issue: gopls/internal/test/integration/bench: add a pull diagnostics benchmark

[gopherbot]

Change https://go.dev/cl/619095 mentions this issue: gopls/internal/cache/analysis: lazily resolve the import map

[gopherbot]

Change https://go.dev/cl/619516 mentions this issue: gopls/internal/cache/parsego: support lazy object resolution for Files

[gopherbot]

Change https://go.dev/cl/622036 mentions this issue: gopls/internal/cache: async pull diagnostics and joined analysis

[gopherbot]

Change https://go.dev/cl/622037 mentions this issue: gopls/internal/cache: memoize cache keys

[gopherbot]

Change https://go.dev/cl/622038 mentions this issue: gopls/internal/cache: share type checking with analysis