Web console: new Ace, diff view, and cleanup. Decorating the console for the holidays ✨ 🎁

[vogievetsky]

At a high level this PR adds a DiffDialog to visualize the change in supervisor specs between edits. This PR also upgrades the Ace editor (the main code editor for all the JSONs and SQLs). This is done by upgrading to the latest version or react-ace which in turn changes how the Ace editor itself is imported from using brace to using ace-builds (see the readme of react-ace for more details on why).

New Diff view:

Updated auto suggestion styling to be more on brand:

So here are the changes that generate the diffs:

• Switched from brace to ace-builds which generates a large number of dependent package and license changes
• Updated to new ReactAce and went everywhere updating the APIs (there are many changes on the JS and the CSS endpoints)
• Normalized the capitalization and spelling of all the describe labels
• Pulled out all the Ace editor styles into a single file ace.scss

This PR has:

• been self-reviewed.
• been tested in a test Druid cluster.

[FrankChen021]

Do we need to handle the HTML tags in the function description?

[vogievetsky]

Great catch!

[vogievetsky]

This is even a bug on master!

[vogievetsky]

Fixed and updated the screenshot in the description

[vogievetsky]

Just realized that I updated the description with a screenshot for a different function than the one we were talking about, so here it is also:

[clintropolis]

lgtm, pulled locally and clicked around a bit, supervisor diff stuff is pretty cool 👍