Incorrect parse result for filters with outer/wrapped brackets

[kirrg001]

NQL returns a wrong parsed result if filters are wrapped with outer brackets.

Let's assume you pass this filter: filter=featured:true,(tags:animal+tags:classic)

It results in:

{"$or":[{"featured":true},{"$and":[{"tags":"animal"},{"tags":"classic"}]}]}

Which is correct!

But if you pass a filter like this: filter=(tags:animal+tags:classic)

It results in:

{"yg":{"$and":[{"tags":"animal"},{"tags":"classic"}]}}

Which is wrong.

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Reference: yg expression, see.