UI: Keep weak stream output ref in status bar

[RytoEX]

Description

The status bar doesn't currently own its references to outputs, which can be a problem if streaming outputs are released soon after stream stop. The Multitrack Video output does exactly that, so the status bar will sometimes try to access an invalid pointer for updating its stats. Keeping a weak reference around and upgrading it to collect stats, similar to how the stats window behaves.

Motivation and Context

Picked from #10633. Want to pull some commits out of that PR to make that PR smaller.

How Has This Been Tested?

This has been tested in the Twitch Enhanced Broadcasting beta.

Types of changes

• Tweak (non-breaking change to improve existing functionality)

• Code cleanup (non-breaking change which makes code smaller or more readable)

Checklist:

• My code has been run through clang-format.
• I have read the contributing document.
• My code is not on the master branch.
• The code has been tested.
• All commit messages are properly formatted and commits squashed where appropriate.
• I have included updates to all appropriate documentation.

[RytoEX]

If pulling commits out of #10633 isn't helpful, we can close this. I find it easier to review small PRs and had offered to start pulling commits out of that PR, so I wanted to start working towards that.

[gxalpha]

Seems sane. If we’re not holding a strong reference we should not access the pointer (and if we were holding one we should listen to the appropriate signals to release it).

That said, this same thing should probably be applied to recordOutput too (even if it’s not causing crashes right now). I’d even consider this in-scope for this PR seeing how similar it is.

[cg2121]

If you are doing this for the streaming output, you should also do the recording output.

[RytoEX]

Regarding the recording output, while I initially had the same thought, the original commit in #10633 only addresses streaming output. I don't want to expand scope too much. I just want to trim down that PR. I can make a follow-up PR for recording output later.