Add Idle State Option for Remote Transmitter Configuration

**Describe the problem you have/What new integration you would like**

For some configurations of IR Emitter circuits (ie. the high power output of the Xiaomi Mijia IR Controller - ESP32 Single Core), a certain idle state is required (in this case high), otherwise the transistors and LEDs remain on and heat the board.

**Please describe your use case for this integration and alternatives you've tried:**

Setting the output inverted prevents the board from getting hot, but also sends incorrect IR signals. Tested with devices and with AnalysIR.

Setting up the output (Xiaomi GPIO26) as a GPIO switch results in:
* ON / High > Transistors Off / Cool.
* OFF / Low > Transistors On / Hot.

Adding something like "idle_state: high"/"idle_state: low" to the "remote_transmitter" configuration options and then using these states when not sending IR would solve this issue.

**Additional context**

Current Yaml file used for testing:
https://github.com/AdamKGoddard/XiaomiIR_ESPHome/blob/master/xiaomi_ir.yaml

Start with the referenced xiaomi_ir.yaml and trace the remote_transmitter configuration entry point for the Xiaomi GPIO26 setup. Determine how an idle_state option should control the output when no IR signal is being sent, while preserving correct IR transmission; verify the result against the described cool and hot GPIO states.

Written by the indexing model from the issue text.