Add airplay2 build of shairport-sync for testing

[linknum23]

Steps to add support for a single fully featured airplay2 stream

• Add shairport-sync binary built for aiplay2
• Add nqptp dependency (needs to be installed from source for now)
• Test single airplay 2 stream with additional airplay 1 streams
• Add support for single airplay 2 stream, with the second stream either being rejected or converted to airplay 1 (depends on above)
• Add metadata using MPRIS support from Use Spotifyd instead of vollibrespot to get latest librespot changes #366 (old metadata is broken with ap2 and already needed to be upgraded to support user control)

[codecov-commenter]

Codecov Report

Merging #378 (970ffa9) into main (6dd7492) will decrease coverage by 1.06%.
The diff coverage is 0.00%.

@@            Coverage Diff             @@
##             main     #378      +/-   ##
==========================================
- Coverage   56.81%   55.75%   -1.07%     
==========================================
  Files          12       12              
  Lines        2920     2920              
==========================================
- Hits         1659     1628      -31     
- Misses       1261     1292      +31     

Flag	Coverage Δ
unittests	55.75% <0.00%> (-1.07%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
amplipi/streams.py	41.62% <0.00%> (ø)
amplipi/app.py	77.88% <0.00%> (-7.62%)	⬇️

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[linknum23]

At the moment we have one working Airplay 2 Stream, without metadata support. Supporting a single airplay 2 stream is looking very promising.

NOTE: Multiple Airplay 2 streams will require a significant effort and some experimentation to integrate docker audio streams into our ALSA configuration and is not part of this PR.

[linknum23]

One option to support multiple Airplay 2 instances sans docker may be to use MVLAN in bridged mode, spinning up one virtual LAN per airplay 2 instance (or just having 4 default ones instantiated at boot time). Need to investigate how feasible this is and if multiple NQPTP servers can be run like this.

[linknum23]

We should probably wrap this PR soon. I think there are a couple of routes to finish this, since we can only support 1 airplay2 stream right now:

1. Add checking to only allow a single airplay2 instance at a time (unable to run additional airplay1 instances)
2. Downgrade additional running airplay2 instances to airplay1 (we would probably use an additional flag to determine which streams want to be airplay2)
3. Wait until we can support multiple aitplay2 instances

[zetlen]

We should probably wrap this PR soon. I think there are a couple of routes to finish this, since we can only support 1 airplay2 stream right now:

• Add checking to only allow a single airplay2 instance at a time (unable to run additional airplay1 instances)

• Downgrade additional running airplay2 instances to airplay1 (we would probably use an additional flag to determine which streams want to be airplay2)

• Wait until we can support multiple aitplay2 instances

Hey, I know this is an old comment and you may have already made a decision, but I strongly endorse releasing option 1 for now, and backlogging support for options 2 and 3. There's a huge advantage to having even one airplay 2 stream, for home theater users and for people trying to explain to family and friends why playing from iPhones is "all weird and slow". Thanks in advance, and thanks a million times for all your work up to this point.

[linknum23]

We are actually working on a simple version of 2 right now with the plans of getting a prerelease out soon.

[linknum23]

Closing this since this work is being finalized in airplay1and2