Handle UUID's correctly for both DBMs

[yhabteab]

This PR adds support for UUID binary and text format in all UI activities involving UUIDs. For this to work, I've introduced a new UUID behavior in IPL orm that is used to automatically convert UUIDs between binary and text formats for MySQL but is a no-op for PostgreSQL as PDO treats the binary format as a string when not explicitly told otherwise via the PDO::PARAM_LOB parameter. Since I've no way to do that parameter binding in all possible cases, I've decided to leave PostgreSQL as-is.

I've also updated the API handlers to partially use the Models instead of raw SQL queries via ipl SQL, so that the UUID can be used in those cases as well. The API handlers are still using raw SQL queries in some places, but I've added an explicit conversion to binary format for those cases, so that the UUIDTransformer is not needed there.

Lastly, I've extended the ObjectSuggestionsCursor class to require the column name for which the suggestions are being generated, and the registered model behaviors the column belongs to, so that it also applies the behaviors, including the UUID behavior to the suggestions.

Context

• Add missing external_uuid fields & change type to binary(16) in MySQL icinga-notifications#496

[yhabteab]

Changed as requested but all the tests fail because of this dependency.

• Introduce UUID behavior ipl-orm#172

[nilmerg]

Still need to test, but code looks fine.

[yhabteab]

I've addressed all your requested changes apart from #547 (comment) because it doesn't make any sense to me.