Improve Embed UI

[kreynen]

• Add icon to Embed tab
• Format filter options to minimize form
• Add inline documentation links

[alexfinnarn]

Finishing this ticket is blocked by #1118

PR in CuBoulder/cu_digital_campaign_bundle#16

[cathysnider]

Testing note: lots of difficulty in getting the test site to recognize the new code asset. Test sites keep wanting to use the old one.

Example One: https://www-dev.colorado.edu/p14d966617ad/ On this site, go to config/atlas and note that there are two digital campaign bundles; the most recent one is checked but the site doesn't recognize it; i.e. it has not enabled the Digital Campaign Bundle.

Example Two: https://www-dev.colorado.edu/p17face92665/ This site has both DC bundles enabled; it is using the old unfixed code, not the new stuff.

[alexfinnarn]

I removed the older code asset on https://www-dev.colorado.edu/p14d966617ad, and now it appears ready for testing.