sql: support preferred binary operators

[cockroach-teamcity]

Exalate commented:

cockroachdb/cockroach#70066 --- Release note (sql change): Placeholder values can now be used as the right-hand operand of the JSONFetchVal (->) and JSONFetchText (->>) operators without ambiguity. This argument will be given the text type and the "object field lookup" variant of the operator will be used. Release justification: None

Jira Issue: DOC-1304