What does this implement/fix?

Add an SDL platform to binary sensor to enable generic keyboard inputs. Without this, encoder and keypad based GUIs are difficult to evaluate on the host platform.

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)
• Code quality improvements to existing code or addition of tests
• Other

Related issue or feature (if applicable):

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

• Add docs for SDL binary sensor esphome-docs#4644

Test Environment

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

Example entry for config.yaml:

esphome:
  name: sdl

host:

logger:

display:
  - platform: sdl
    dimensions:
      width: 320
      height: 320
    auto_clear_enabled: false 

binary_sensor:
  - platform: sdl
    id: key_up
    key: SDLK_a
  - platform: sdl
    id: key_down
    key: SDLK_d
  - platform: sdl
    id: key_enter
    key: SDLK_s

lvgl:
  encoders:
    enter_button: key_enter
    sensor:
      left_button: key_up
      right_button: key_down

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.