Support Ignored State

[EJH2]

Part 3 of 4 in the saga that is #54. Significant changes in this PR:

• Added IGNORED state support to Progress.get_info().
• Added onIgnored funtion to JS (as well as the associated color).
  • Default configuration looks like so:
    
    If a user specifies an error message (i.e. doing raise Ignore('lol')), it will use the error message instead like so:
    
• Added a cleaner and clearer default settings visualization for barColors, taking the form of a table.
• Added a post-run handler to the base package to make sure that the HTTP progress bars properly receive the ignored event.
  • This is an unfortunate but necessary change, as without the post-run handler updating the backend, the backend will only show the last progress update it received. This is obviously less than ideal since the intent is to disconnect the task.

All that's left from the aforementioned issue is to investigate the behavior of store_errors_even_if_ignored, although I believe Omar was going to take a crack at that. Suggestions welcome.

[czue]

This looks great - appreciate you breaking everything up by commit and also the README improvements! 👏 👏

[OmarWKH]

This is great.

My preference is against a solution that requires updating the state after being ignored. But I understand that it might not be doable otherwise :)

[OmarWKH]

Does WS get an IGNORED state without this post handler?

[EJH2]

Yes, the WS receives the IGNORED state from it's own post handler, this is necessary purely to update the state on the backend so that the AsyncResult in the HTTP view can be notified that it's been ignored, as the point of the IGNORED state is to not save anything to the backend.

[OmarWKH]

All that's left from the aforementioned issue is to investigate the behavior of store_errors_even_if_ignored, although I believe Omar was going to take a crack at that. Suggestions welcome.

Sorry. Might be a while before I test it. But however it works, it shouldn't block this PR.