Update schema name of platform components to be <name>_schema

Platform components, e.g. sensor, binary_sensor, stepper, they used to export the config schema as `PLATFORM_SCHEMA` that was long ago, then they changed to `_SCHEMA` e.g. `SENSOR_SCHEMA`, `BINARY_SENSOR_SCHEMA`, `STEPPER_SCHEMA` see https://github.com/esphome/esphome/blob/7ad6dab3839686ec64ba15de4d0a10c41e506346/esphome/components/cover/__init__.py#L151 and a global search of `# Remove before 2025.11.0`

now platform schemas are going to be normalized to _schema() as a `func()`, not `CONSTANT`

almost all (seems like e.g. stepper is missing) are already done, but also need to make sure these are using a consistent argument list so the json schema can call these functions to infer the platform schemas