timezone validator and tests
#6678 - timezone validator constructor simplification
#6678 - timezone validator constructor simplification
#6678 - moving protected method at the bottom of the class
#6678 - simplified `calculateTypeValue`
#6678 - adding tests to verify that invalid checked types are rejected with an exception
#6678 - coverage annotations
#6678 - better exception messages for invalid types
#6678 - better exception messages for invalid types
Merge branch 'feature/#6678-timezone-validator' into develop

Close #6678