CAPI: Actually try to use Refresh Token if CAPI says unauthorized

The refactor for threaded CAPI worker has inadvertently caused us to
always try *full* re-auth when the CAPI signals the Access Token is
expired.

EDMarketConnector.py

@@ -1159,6 +1159,13 @@ class AppWindow(object):
             # LANG: Frontier CAPI server error when fetching data
             self.status['text'] = _('Frontier CAPI server error')
 
+        except companion.CredentialsRequireRefresh:
+            # LANG: Frontier CAPI Access Token expired, trying to get a new one
+            self.status['text'] = _('CAPI: Refreshing access token...')
+            if companion.session.login():
+                logger.debug('Initial query failed, but login() just worked, trying again...')
+                companion.session.retrying = True
+
         except companion.CredentialsError:
             companion.session.retrying = False
             companion.session.invalidate()

companion.py

@@ -265,6 +265,15 @@ class CredentialsError(Exception):
             self.args = (_('Error: Invalid Credentials'),)
 
 
+class CredentialsRequireRefresh(Exception):
+    """Exception Class for CAPI credentials requiring refresh."""
+
+    def __init__(self, *args) -> None:
+        self.args = args
+        if not args:
+            self.args = ('CAPI: Requires refresh of Access Token',)
+
+
 class CmdrError(Exception):
     """Exception Class for CAPI Commander error.
 
@@ -772,6 +781,7 @@ class Session(object):
                 self.dump(r)
 
                 if r.status_code == 401:  # CAPI doesn't think we're Auth'd
+                    # TODO: This needs to try a REFRESH, not a full re-auth
                     # No need for translation, we'll go straight into trying new Auth
                     # and thus any message would be overwritten.
                     raise CredentialsError('Frontier CAPI said Auth required') from e