Improve workspace service
- Remove legacy workspace object
- Remove references to hasWorkspace, hasFolderWorkspace, hasMultiFolderWorkspace by introducing getWorkbenchState with Empty, Folder, Workspace states
- Check for places using null check on workspace object and adopt it by using the WorkbenchState or Workspace folders
- Rename roots to WorkspaceFolder

Fixes #34119

Fix broken API link per vscode-docs PR #1142

Fixes #34332

Fixes #34328

Fixes an exception with selection in the terminal, see sourcelair/xterm.js#989

Fixes #27961

Adds a new `editor.lightbulb.enabled` setting to enable/disable the code actions lighbulb. You can still trigger code actions manually