upgrade-field-literals should do case-insensitive fixes (#19713)

...box/query_processor/middleware/row_level_restrictions.clj

...uery_processor/middleware/row_level_restrictions_test.clj

...tabase/query_processor/middleware/add_source_metadata.clj

src/metabase/query_processor/middleware/resolve_fields.clj

...ase/query_processor/middleware/upgrade_field_literals.clj

src/metabase/util.clj

...uery_processor/middleware/upgrade_field_literals_test.clj

test/metabase/query_processor_test.clj

test/metabase/query_processor_test/explicit_joins_test.clj

test/metabase/query_processor_test/nested_queries_test.clj