Floating Button Trigger

[fpcorso]

This would add a new floating, fixed button on the site. Once clicked, it will open a popup. Clicked again, it would close the popup.

Similar to the HelpScout Beacon.

@danieliser Had outlined some ideas for implementation: As for where it goes that could probably be a new trigger type. In this way, it follows the targeting of the popup it's used on.

1. New trigger type: Fixed Button or similar.
2. Trigger options might include:

• Should offer delay like time delay.
• What should be shown: Button or Popup
• Should the button disappear when popup open?
• Should the button stay when the popup closes?

Alternatively, it could be added to a new tab/subtab as settings that just work with any trigger, but the same settings likely.

3. There should be new settings in the popup theme editor to support styling the floating button.

The original discussion was on #396