Better support for non-workspace activation

[Ketho]

Branching off from https://github.com/Ketho/vscode-wow-api/issues/180#issuecomment-2764826235 for @MattZeeX and @JustArion

There is the use case of writing e.g. WeakAuras in a Lua file, or a new untitled text file that will be automatically be detected as Lua when writing code, naturally while not in a workspace.

The "Activate WoW API extension" command is misleading:

• (bug) When the user is in a workspace but not in one with a .TOC file from an addon, using the command does nothing currently. The expected behavior is to properly activate in either Workspace/User settings.json.
• When the user is not in a workspace, it does nothing. Even when the User scope configuration is enabled. The expected behavior is to properly activate in the User settings.json, or otherwise inform the user why it cannot activate outside of a workspace.

(feature) There needs to be diagnostic logging so users can see what the extension is trying to do when reporting issues.

I always assumed people were working with WoW addons in workspaces and did not think about other use cases. I should also provide better documentation and reasoning why the extension prefers using Workspace scope instead of User scope settings on the wiki.