Make type and type_version mandatory on policies

Up until now, the "type" and "type_version" fields defaulted to "NULL"
and "0.0.0" respectively when they were not specified because the
"type_version" field was not always specified on policies in previous
releases. In cases where the "type_version" field was not specified, it
was assumend that a "0.0.0" version of the policy type existed. In
parallel, if the version field was not specified on the policy type, the
version was stored as 0.0.0.

This behaviour is now changed and the "type" and "type_version" fields
are now always mandatory.

Issue-ID: POLICY-2538
Change-Id: Ieec97f4a111edd13dbe31116c7549f07c19ef0aa
Signed-off-by: liamfallon <liam.fallon@est.tech>