chore: Aggregation groupings for by() and without()

[spiridonov]

What this PR does / why we need it:

This PR introduces proper groupings (a list of columns and a mode by/without). Previously it was represented only a s list of columns and without was not supported at all.

• aggregator is changed to aggregate by an arbitrary variable list of labels. The resulted record will have a union of all columns seen during aggregation.
• Pushdown optimizations are changed. For example, if a range aggregation has without () we have to read all columns from data objects and nothing can be pushed down.
• Printers are changed to reflect gropings mode.
• Proto changes for physical plans.

Which issue(s) this PR fixes:
Fixes #

Special notes for your reviewer:

Checklist

• Reviewed the CONTRIBUTING.md guide (required)
• Documentation added
• Tests updated
• Title matches the required conventional commits format, see here
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