Query Builder. Add filter prop "isNestedQuery" rather than using 'in'/'notIn' strings conditions

[ivanvpetrov]

Is your feature request related to a problem? Please describe.

Currently, for some logic around nested queries, we use conditions with 'in'/'notIn' strings which is not ideal.

Describe the solution you'd like

Add a new prop "isNestedQuery" to IFilteringOperation and use that in those conditions. This will also leave the door open for creating custom filters triggering nested query creation