Proposed change

After the recent overhaul of the kodi integration, the media player entity is unavailable when Home Assistant starts until the related kodi instance comes online. This prevents the power button from showing up on the media player card.
This PR changes the behavior so the media player entities are off at startup, allowing for power-on actions through the UI.
The changes are largely based on changes made by alexanv1@571780f with some additional fixes as mentioned in the discussion of the issue at #40450

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 Since 0.115 Kodi goes "unavailable" state if turned off when HA restarts #40450 and fixes Kodi entity is "off" for long time after kodi is back online #43269 and fixes Kodi integration spams HA log with Not Ready messages #40970 and fixes With 0.115 kodi.call_method calls only work a few minutes after Kodi has started #40482
• This PR is related to issue: Since 0.115 Kodi goes "unavailable" state if turned off when HA restarts #40450
• Link to documentation pull request: N/A

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][dev-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:

• (N/A) Documentation added/updated for [www.home-assistant.io][docs-repository]

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

• The [manifest file][manifest-docs] 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][quality-scale]:

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