x/tools/gopls: experimental LSP dialog support

[h9jiang]

This is a feature request in gopls to experiment with LSP methods with dialog support. See more at microsoft/language-server-protocol#1164.

The purpose of this feature request is experimenting potential solutions that could fulfill the requirement of microsoft/language-server-protocol#1164. A solution can be either or combination of:

• Altering existing LSP methods. (twisting the purpose or introducing arguments of existing LSP)
• Proposing new LSP methods.

A few gopls/vscode-go feature request could benefit from this:

• golang/go#57016: support move type refactoring.
• golang/go#70583: support move declaration refactoring.
• golang/go#38028: support change signature refactoring.
• golang/vscode-go#2002: migrate gomodifytags require input from users.

The experiment will based on gopls + vscode-go.

[gopherbot]

Change https://go.dev/cl/721540 mentions this issue: gopls/internal/protocol: add form field in type CodeAction

[gopherbot]

Change https://go.dev/cl/722241 mentions this issue: gopls/internal/server: embed structured data in code action's data

[gopherbot]

Change https://go.dev/cl/722244 mentions this issue: gopls/internal/integration: move CodeActionByKind to package integration

[gopherbot]

Change https://go.dev/cl/722245 mentions this issue: gopls/internal/test/integration: add codeAction/resolve in fake editor

[gopherbot]

Change https://go.dev/cl/722244 mentions this issue: gopls/internal/test/integration: move CodeActionByKind to package integration

[gopherbot]

Change https://go.dev/cl/722740 mentions this issue: gopls/internal/protocol/generate: move injections to tables.go