Allow actions in web_server to be executed via GET method

[afarago]

What does this implement/fix?

Allow actions to be executed via GET methods as well.

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

Detailed use

My use case: allow simple local network webhook usage from a Shelly device.

This can be called as http://<ip_address>/button/template_button/press

Related issue or feature (if applicable): fixes
not applicable

Pull request in esphome-docs with documentation (if applicable): esphome/esphome-docs#
not applicable

Test Environment

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

Example entry for config.yaml:

# Example config.yaml
web_server:

button:
  - platform: template
    name: "Template Button"
    on_press:
      - logger.log: Button Pressed

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.

[github-actions]

There hasn't been any activity on this pull request recently. This pull request has been automatically marked as stale because of that and will be closed if no further activity occurs within 7 days. Thank you for your contributions.