Media changes including support for PRIM_MEDIA_FIRST_CLICK_INTERACT and HUD autoplay

[DarlCat]

This PR does three things which were relatively difficult for me to decouple:

1. Adds conditional support for PRIM_MEDIA_FIRST_CLICK_INTERACT to the viewer
   • Closes Enable PRIM_MEDIA_FIRST_CLICK_INTERACT conditionally in the viewer #3785
2. Adds a new setting for media auto-play on HUDS
3. Shuffles the sound & media tab just a bit to make space for these new goodies while cleaning up some forgotten XUI attributes on WebRTC settings. Creating room for both of these options made separate PRs less attractive, as I think everyone would agree less XUI merging the better.
4. Adds a test plan for the feature which covers the individual operational modes it offers.

Settings added are:

MediaAutoPlayHuds (bool) Allows web media on HUDs to autoplay even if the user disables autoplay for inworld media
MediaFirstClickInteract (s32) Determines which (if any) objects are able to skip the focus click for their media

While adding coverage for media first click interact I discussed the feature with a few people, and it was determined that also passing hover events to media contexts without explicitly granting focus was also expected, the biggest reason was support for things like hover tips and hover controls on webpages.

I admit that XUI is nowhere to be found on my list of strengths, so I apologize in advance for what I've done. If there is any input on how to improve anything about this PR I warmly welcome feedback. I wanted to make sure that everything fit, and it didn't look too terribly thrown together. It may be time to think about breaking this preferences category up, or moving into tabs. With WebRTC voice changes and additional settings from that likely, a section for voice alone would make a lot of sense and de-clutter this area a lot.

Lastly, a screenshot of the modified sound & media preferences panel for first impressions

This PR is a recreation of #3989 which was targeting the incorrect branch, and is unable to be reopened.

[marchcat]

Thank you!

The test plan is 🔥
XML change looks cleaner now too.

[DarlCat]

I realized laying in bed last night (I know, sad) that I probably forgot to enable the all MOAP UI option, so I just pushed a commit just now that flips that on. The test plan already covers manually activating that with debugs (case 8) so it shouldn't be a blocker requiring a whole new build for testing since it's a tiny XUI change 🤞

[Geenz]

@Dan-Linden @AtlasLinden As a heads up for test plans, a test plan is included at doc/testplans/PRIM_MEDIA_FIRST_CLICK_INTERACT.md

This generally looks good. Merging it into develop - should make it into the next release.

Thank you!