Refactor message file structure

[olemis]

Is your feature request related to a problem? Please describe.
There are many (unrelated) message definitions in a single file.

Describe the solution you'd like
Group messages by similar purpose .

• Coin-specific messages in messages-${COIN}.proto file
• Bootloader messages in message-bootloader.proto file
• Generic reusable messages in message-common.proto file
• Messages for cryptographic operations in message-crypto.proto file
• Debug messages in message-debug.proto file
• Management messages in message-management.proto file
• Web authentication messages in message-webauthn.proto file
• Message integer IDs in message.proto file
• Script to merge them into a single file

Describe alternatives you've considered
Keeping a single file is unmanageable not an option

Additional context
Based on Trezor definitions.