Merge remote-tracking branch 'origin/feature/7114_ModeratorTzeroLinear'
Migrate all tests using automated script. Refs #6614
More Python v1->v2 updates.
Fix Offspec test and example test after migration. Refs #6614
Allow numpy boolean in return value of validate method. Refs #6614
Migrate PEARL system tests.

Pass by value and not string leads to very minor differences in GSS file
but the level is acceptable.
Refs #6614
Move IndirectDiffractionTest to new API. Refs #6614
Merge branch 'feature/6614_api_migrate' into develop