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
Fix tests for new API. Refs #6614
Use Load rather than LoadNexus in validation. Refs #6614
Pull some tests back to old API. They depend on old API algorithms.

Refs #6614
Fix more tests for new API. Refs #6614
Remaining fixes for v2 API tests. Refs #6614
Pull back a few EQSANS tests to the old API.

They all have counterpart tests for the new API and will just be removed when
API itself is removed.
Merge remote-tracking branch 'remotes/origin/feature/6614_api_migrate'