Show which state changed events a template listeners for in dev tools

[bdraco]

Requires home-assistant/core#39925

Proposed change

Show which state changed events a template listeners for in dev tools

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

Additional information

• This PR fixes or closes issue: fixes #
• This PR is related to issue:
• 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

[bdraco]

Retest:

[bdraco]

Revised the no listeners case as that will probably get some people.

[bdraco]

Retested markdown card

[bdraco]

Wait for backend pending the decision to cherry-pick home-assistant/core#39925 or not

[bdraco]

Going to test with #39925 reverted to make sure it works when we don't get listeners.

[bdraco]

Verified doesn't error without home-assistant/core#39925 and still works with it

[bdraco]

Retested, looks good