Use pulsectl library for PulseAudio connection

[breiti]

Breaking change

• The default connection honors the configuration in /etc/pulse and no longer defaults to localhost
• When a host is configured, the default port has been changed to 4713 to use the native interface of PulseAudio.
• The config parameters buffer_size and tcp_timeout have been removed.

Proposed change

Get rid of internal library code and use pulsectl library to communicate
with PulseAudio server.

This is a breaking change as the library uses the much more powerful
native interface instead of the CLI interface, requiring the need to
change the default port.

On the bright side, this also solves some issues with the existing
implementation:

• There was no test if the complete list of loaded modules was
  already received. If not all data could be read at once, the
  remaining modules not yet in the buffer were considered absent,
  resulting in unreliable behavior when a lot of modules were loaded
  on the server.

• A switch could be turned on before the list of loaded modules was
  loaded, leading to a loopback module being loaded even though this
  module was already active (pulseaudio: Multiple loopbacks for same switch #32016).

Type of change

• Dependency upgrade
• Bugfix (non-breaking change which fixes an issue)
• New integration (thank you!)
• New feature (which adds functionality to an existing integration)
• Breaking change (fix/feature causing existing functionality to break)
• Code quality improvements to existing code or addition of tests

Additional information

• This PR fixes or closes issue: fixes pulseaudio: Multiple loopbacks for same switch #32016
• This PR is related to issue: pulseaudio: Multiple loopbacks for same switch #32016
• Link to documentation pull request: Update pulseaudio_loopback pulsectl lib (#34965) home-assistant.io#13257

Checklist

• The code change is tested and works locally.
• Local tests pass. Your PR cannot be merged unless tests pass
• There is no commented out code in this PR.
• I have followed the development checklist
• The code has been formatted using Black (black --fast homeassistant tests)
• Tests have been added to verify that the new code works.

If user exposed functionality or configuration variables are added/changed:

• Documentation added/updated for www.home-assistant.io

If the code communicates with devices, web services, or third-party tools:

• The manifest file has all fields filled out correctly.
  Updated and included derived files by running: python3 -m script.hassfest.
• New or updated dependencies have been added to requirements_all.txt.
  Updated by running python3 -m script.gen_requirements_all.
• Untested files have been added to .coveragerc.

The integration reached or maintains the following Integration Quality Scale:

• No score or internal
• 🥈 Silver
• 🥇 Gold
• 🏆 Platinum

[pvizeli]

Look fine, just a small comment about the config

[MartinHjelmare]

Looks good! Just a request for clean up of legacy code.

[MartinHjelmare]

Please rebase on latest dev branch to let the build pass.

[MartinHjelmare]

Looks good!

@pvizeli?

[MartinHjelmare]

@breiti please open a docs PR and update the config section:
https://www.home-assistant.io/integrations/pulseaudio_loopback/#configuration-variables