Implement log bundle support

[lgactna]

When log bundle messages are received, they should be "decompressed" using the corresponding Pydantic model and used to generate one or more Log entries in the database.

A best effort should be made to avoid duplication where possible (i.e. if the log comes from a standard log bundle message with a message ID, check the database for all unique message IDs and assert that this message hasn't been used to generate Log entries already).