Only allow variables in LIMIT clauses if the LIMIT is within a LATERAL subquery

Only allow variables in LIMIT clauses if the LIMIT is within a LATERAL subquery
and the variable resolves to another FROM clause term to the left of the
subquery.  We cannot allow variables from outer contexts because the LIMIT
value is computed before the cursors in the outer context have been initialized.

FossilOrigin-Name: 0a2531c3a3750fd22360595274eb97fa66d17a90502180b7b11adc5b136da5ed