Improve detection of entity names in templates

[amelchio]

Description:

This PR adds filtering of extracted entity names, fixing an issue where variables with invalid IDs made the algorithm not fall back to MATCH_ALL.

Related issue (if applicable): fixes #13398

Example entry for configuration.yaml (if applicable):

      - wait_template: >-
          {{ is_state('media_player.' ~ where, 'playing') }}

Checklist:

• The code change is tested and works locally.
• Local tests pass with tox.

If the code does not interact with devices:

• Tests have been added to verify that the new code works.

[pvizeli]

Please update the regex that he not detect this. All that was we can do on regex, should we do on regex otherwise we slow done this function and make it more cpu/memory hungry

[amelchio]

I think the regex works as intended, it locates where in the provided example.

Instead, I have moved the filter to only affect the variable values that are appended.