Add Voice assistants filter to Entities page

[kritsel]

Proposed change

Follow-up on #28785
Add a 'Voice assistants' filter to the Entities page, allowing the user to filter entities that are exposed to a specific voice assistant (Assist, Alexa or Google).

In scope:

• The filter only lists voice assistant types (Assitant, Alexa, Google Assistant) that are actually active on the HA instance (note: HASS own Assistant is always active) ❓ (untested)
• When enabling or disabling a voice assistant type, the listed filter options must change accordingly ❓ (untested)
• Voice assistant options are listed regardless whether any entities are actually exposed to them (comparable to how the labels filter works) ✔
• Each voice assistant option displays a logo and name ✔
• The filter behaves as any of the other filters ✔

Out of scope:

• Adding the filter to the Helpers, Automations, Scenes and Scripts pages. That can be a follow-up PR once this PR has been approved.

Type of change

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

Example configuration

N/A

Additional information

• This PR fixes or closes issue: fixes #
• This PR is related to issue or discussion:
• Link to documentation pull request:

Checklist

• The code change is tested and works locally.
• There is no commented out code in this PR.
• 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