Quote table and column names for tab completion pluck

MSP-8986

Past!Luke tried to be sloppy and not use the table and column quoting when
inlining the AREL to SQL for attributes.  Without quoting any usage of
the references table throws a PG Error because REFERENCES is a reserved
word in PG as part of the foreign key constraint syntax.
Fix nil operator in specs heisenbug

MSP-8986

Typo in one of the operator names could cause the operator by name look
up to fail.  Added an example to check that all the operator_names are
valid to prevent this in the future.