`Copilot setup failed` message: Could have more information regarding why it failed

[benibenj]

Testing #252839

When a user does not trust the workspace, the user gets the Copilot setup failed message. This message does not include any information regarding what is wrong currently. Consider adding more information regarding the failure for all known scenarios.

For the workspace trust scenario, you could show the message Copilot can't run in untrusted workspace followed by a button/action that runs the workbench.trust.manage command

[bpasero]

This was actually quite buggy I realised: the ask to trust the workspace should come FIRST and only then the sign-in flow.

Changing the wording to this, its not possible for security reasons to show command links in the output: