Send a valid PTS in the RTP video header

[cgutman]

Description

Sunshine is not sending valid timestamps in the RTP header for video traffic. This caused clients that depend on PTS for frame pacing to break (see moonlight-stream/moonlight-ios#538).

I introduced a workaround in moonlight-common-c to unbreak iOS for servers that send broken PTS information (moonlight-stream/moonlight-common-c@bc00d95), but this is the proper server-side fix. PTS is arguably even more important for Sunshine compared to GFE, because Sunshine doesn't send frames at a constant rate (when there is no activity on screen).

Type of Change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation update (changes to documentation)
• Repository update (changes to repository files)

Checklist

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have added or updated the in code docstring/documentation-blocks for new or existing methods/components

Branch Updates

LizardByte requires that branches be up-to-date before merging. This means that after any PR is merged, this branch
must be updated before it can be merged. You must also
Allow edits from maintainers.

• I want maintainers to keep my branch updated

[ReenigneArcher]

I have a fix for the aur build in #524 but hoping they merge my changes upstream sooner, rather than later.