Add support for json in postgres query

[poonai]

Describe the bug
Inspektor doesn't support json query support.

To Reproduce
Parse the following query

select * from tmpdb where cast(meta1->'refferedBy' as text) = '3332'

you'll get the following error

ParserError("Expected an expression:, found: >")

Expected behavior
Inspektor should be able to parse json query

[poonai]

support for json selection is submitted to sqlparser crate

apache/datafusion-sqlparser-rs#458