Fix TAXII2 collection can_read and can_write

[eric-eclecticiq]

1. A missing account would return None that is not a boolean thus not compliant with TAXII 2 Collection specs. taxii2client would raise a validation error.
2. Add tests and types
3. Move can_read and can_write from entity Account to TAXII1 collection
4. Fix sqldb Account permissions setter to accept TAXII2 permissions
5. permissions keys must be a string as once serialized to the DB the UUID knowledge is lost

Others:

1. Class name change oversight: Fix UUID json serialization #289 (comment)
2. Fix docker build deprecation: LegacyKeyValueFormat: "ENV key=value" should be used instead of legacy "ENV key value" format