companion: Improve station() checks and documentation

* Expand on the docstring to point out extra queries might be made.
* Add checks for lastStarport and then name within that being properly
  present and set.

companion.py

@@ -604,7 +604,17 @@ class Session(object):
         return data
 
     def station(self) -> CAPIData:  # noqa: CCR001
-        """Perform CAPI /profile endpoint query for station data."""
+        """
+        Perform CAPI quer(y|ies) for station data.
+
+        A /profile query is performed to check that we are docked (or on foot)
+        and the station name and marketid match the prior Docked event.
+        If they do match, and the services list says they're present, also
+        retrieve CAPI market and/or shipyard/outfitting data and merge into
+        the /profile data.
+
+        :return: Possibly augmented CAPI data.
+        """
         data = self.query(URL_QUERY)
         if 'commander' not in data:
             logger.error('No commander in returned data')
@@ -613,17 +623,33 @@ class Session(object):
         if not data['commander'].get('docked') and not monitor.state['OnFoot']:
             return data
 
-        services = data['lastStarport'].get('services', {})
+        # Sanity checks in case data isn't as we expect, and maybe 'docked' flag
+        # is also lagging.
+        if (last_starport := data.get('lastStarport')) is None:
+            logger.error("No lastStarport in data!")
+            return data
+
+        if ((last_starport_name := last_starport.get('name')) is None
+                or last_starport_name == ''):
+            # This could well be valid if you've been out exploring for a long
+            # time.
+            logger.warning("No lastStarport name!")
+            return data
+
+        services = last_starport.get('services', {})
         if not isinstance(services, dict):
-            # This happens if you're in-ship in-space and force an Update
+            # Odyssey Alpha Phase 3 4.0.0.20 has been observed having
+            # this be an empty list when you've jumped to another system
+            # and not yet docked.  As opposed to no services key at all
+            # or an empty dict.
             logger.error(f'services is "{type(services)}", not dict !')
             if __debug__:
                 self.dump_capi_data(data)
 
+            # Set an empty dict so as to not have to retest below.
             services = {}
 
-        last_starport_name = data['lastStarport']['name']
-        last_starport_id = int(data['lastStarport']['id'])
+        last_starport_id = int(last_starport.get('id'))
 
         if services.get('commodities'):
             marketdata = self.query(URL_MARKET)