feat(oauth2): handle refresh token expiration

[fioan89]

Refresh tokens can expire after a certain amount of time. The expiration can happen during a live session or when the Toolbox is closed.
Inspecting the coder code it looks like 400 Bad request is raised

{
  "error": "invalid_grant",
  "error_description": "The refresh token is invalid or expired"
}

when we try to refresh an access token with an expired refresh token. Coder Toolbox should be able to handle this scenario.

[fioan89]

Also take into account if client_id is not accepted:
If refresh_token is rejected -> get a new refresh token using the already registered client
If client_id is rejected -> register a new client

[fioan89]

Also there is an ongoing discussion over at #209 (comment) The discussion from that PR is thigtly coupled with how we will have to handle errors during token refresh:

[code-asher](https://github.com/code-asher)
[2 days ago](https://github.com/coder/coder-jetbrains-toolbox/pull/209#discussion_r3042141254)
If the refresh fails, do we need to look at the response and possibly discard the token? If it is some kind of permanent auth failure. Otherwise I imagine we would keep trying to refresh with the same token.

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@[fioan89](https://github.com/fioan89)
fioan89
[2 minutes ago](https://github.com/coder/coder-jetbrains-toolbox/pull/209#discussion_r3054159645)
I think I'll log an issue. There are transient reasons (network failure??) for which it is worth retrying at the next API call. But for other errors like invalid_grant or unauthorized_client it is probably pointless to retry again. And it is not easy to tackle this problem - do we disrupt the user and remove his workspaces, stop the ongoing ssh connections and popup the login screen, or do we stop the world but still keep the workspaces visible? I think it is worth pondering over and maybe involve @matifali in the discussion, but in a separate ticket.