add support for FOR ORDINALITY and NESTED in JSON_TABLE

[lovasoa]

fixes #1492

see the specs here: https://dev.mysql.com/doc/refman/8.0/en/json-table-functions.html#function_json-table

@alamb : this is a fix for the following bug in SQLPage: sqlpage/SQLPage#658

[iffyio]

LGTM! cc @alamb

[coveralls]

Pull Request Test Coverage Report for Build 11621463747

Warning: This coverage report may be inaccurate.

This pull request's base commit is no longer the HEAD commit of its target branch. This means it includes changes from outside the original pull request, including, potentially, unrelated coverage changes.

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Details

• 27 of 29 (93.1%) changed or added relevant lines in 3 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage increased (+0.003%) to 89.382%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
src/ast/query.rs	10	12	83.33%

Totals
Change from base Build 11580333290:	0.003%
Covered Lines:	30439
Relevant Lines:	34055

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💛 - Coveralls

[alamb]

Thanks @lovasoa and @iffyio

[lovasoa]

Thank you for merging, @alamb 😊

Could you maybe also take a look at #1490 ?