Add grouping-set and window-frame SQL helpers

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What this task asks for

Add grouped aggregation clauses, window frame builders, null-handling modifiers, and related SQL function helpers. Add cube, rollup, and grouping-set query-builder methods that compose with existing grouping. Compile grouping sets with per-set parentheses while keeping cube and rollup contents flat. Strip only SQL-standard implicit RANGE extents in `SimplifyFramePlugin`. Add ROWS, RANGE, and GROUPS extent builders with two-sided bounds and exclusion modifiers. Accept numeric or expression offsets while parameterizing numeric extent values. Add typed ranking and value accessors plus null-respect and null-ignore modifiers.