* Add unit test to verify the format of message detail strings
(max line length of 80 chars)
* Add unit test to verify non-null, non-empty message strings
* Tidy up a number of messages (to pass unit tests)
* Add message details for all kmw compiler messages
* Add a clickable link for the TIKE message window for each message
so that explanations and further message details are more accessible
to authors (`kmc message` is already available for command-line users)
* Fixes a number of minor issues with the messages window in TIKE,
mostly relating to when popup menu commands are enabled and how
messages are selected.
Fixes: #13134
