feat(login): add status command (#1087) (#1105)

Implements #1087.

Adds `tea login status [<login name>] [-o <format>]`, which verifies the stored token for one or all configured logins and reports:

- login name/URL and default status
- whether the token is valid (via `GET /api/v1/user`)
- auth method and token expiry
- whether the git credential helper is configured

Machine-readable output is available via the usual `-o` formats with fields `name`, `url`, `user`, `valid`, `auth_method`, `token_expiry`, `helper`, and `default`.

Reviewed-on: https://gitea.com/gitea/tea/pulls/1105
Reviewed-by: bircni <bircni@icloud.com>

modules/config/login.go

@@ -446,6 +446,14 @@ func (l *Login) Client(options ...gitea.ClientOption) *gitea.Client {
 		os.Exit(1)
 	}
 
+	return l.ClientWithoutRefresh(options...)
+}
+
+// ClientWithoutRefresh returns a client to operate the Gitea API without
+// attempting an automatic OAuth token refresh. Commands that need to handle
+// token refresh errors themselves (such as 'tea login status') should use this
+// instead of Client, which prints to stderr and exits on refresh failure.
+func (l *Login) ClientWithoutRefresh(options ...gitea.ClientOption) *gitea.Client {
 	// Configure transport-level timeouts so a stalled or unresponsive server
 	// fails fast instead of hanging forever. These bound connection setup and
 	// time-to-first-response-byte only, so slow-but-progressing transfers (e.g.