Migrate away from deprecated Platform/Board Configurations

[barndawgie]

Per current ESPHome documentation, the Platform and Board settings under esphome are deprecated.

@bitfliq indicated this is preventing him from making some desired configuration updates: https://discord.com/channels/1148015790038188073/1148015790520541246/1196697510840897547

[barndawgie]

At first glance, this isn't a super-hard change to make, but it may not be possible without breaking existing configurations.

[segdy]

Yes, I have exactly the issue right now that I need to tune items (framework type) but can't because of the old format.

[segdy]

Created a pull request: #422

Hopefully it makes it in, otherwise it's impossible to use Atom S3 Lite for example