Fix editor live validation

[bdraco]

What does this implement/fix?

This broke in 25ab6f0 because read_config_file was no longer being called. It was missed that read_config_file will check the CORE.vscode and CORE.ace globals, and in some cases instead of reading a config file from disk, it will print an event to stdout, and than decode json from stdin to get the contents of the yaml.

def read_config_file(path: str) -> str:
    if CORE.vscode and (
        not CORE.ace or os.path.abspath(path) == os.path.abspath(CORE.config_path)
    ):

This PR removes read_config_file since its no longer used, which removes more of the global CORE.ace and CORE.vscode checks.

There are still two places where these global checks remain that should be removed, but they are a bit harder to remove and not contemplated in this PR

esphome/config_validation.py:        not CORE.ace or os.path.abspath(path) == os.path.abspath(CORE.config_path)
esphome/config_validation.py:        not CORE.ace or os.path.abspath(path) == os.path.abspath(CORE.config_path)

I added some more typing since it was very hard to follow what was going on as the variables names were not obvious.

Types of changes

• Bugfix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Other

Related issue or feature (if applicable): fixes esphome/issues#5533

Pull request in esphome-docs with documentation (if applicable): esphome/esphome-docs#

Test Environment

• ESP32
• ESP32 IDF
• ESP8266
• RP2040
• BK72xx
• RTL87xx

Example entry for config.yaml:

# Example config.yaml

Checklist:

• The code change is tested and works locally.
• Tests have been added to verify that the new code works (under tests/ folder).

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

• Documentation added/updated in esphome-docs.

[bdraco]

It would be nice to add tests for this, but in its current form its not very testable, and I didn't want to refactor it here.