Migrations should have unless exists validations

[laritakr]

Story

To avoid migration errors in multi-tenant applications, migrations should be wrapped with:

unless table_exists?(:iiif_print_table_name)
.
.
.
end

There are no column changes or index changes, but if there were, those would be wrapped with unless column_exists? or unless index_exists?

See examples in British Library migrations

Acceptance Criteria

• Modify all migrations to wrap with an existence check prior

Screenshots / Video

Testing Instructions and Sample Files

Notes