Ensure DISTINCT aggregates share branch only with matching ORDER BY - #27852

…uckdb#27852)

Non-argument ORDER BY expressions become deduplication keys of the
shared distinct branch, so merging an ordered DISTINCT aggregate into a
set changed which rows the other members treated as duplicates. Two
aggregates now only share a DistinctAggregateSet when their non-argument
ORDER BY expressions match.

Fixes duckdb#27815

Co-authored-by: KassaSana03 <[email protected]>

## Summary

Backports the PRs labeled `backport v2.0-cyanoptera` that are merged
into `main` and not yet on this branch (oldest-first), as one squash
commit per PR with the original author (`Co-authored-by` for further
authors):

duckdb#27958, duckdb#27869, duckdb#28043, duckdb#28065, duckdb#28066, duckdb#27690, duckdb#28046, duckdb#28042, duckdb#28074,
duckdb#28056, duckdb#28037, duckdb#28073, duckdb#28005, duckdb#28016, duckdb#28076, duckdb#28104, duckdb#28108, duckdb#28087,
duckdb#28097, duckdb#27767, duckdb#27998, duckdb#28029, duckdb#28121, duckdb#28119, duckdb#28120, duckdb#28109, duckdb#28117,
duckdb#27916, duckdb#28118, duckdb#27860, duckdb#28114, duckdb#27923, duckdb#27804, duckdb#28098, duckdb#27915, duckdb#27930,
duckdb#28213, duckdb#28217, duckdb#28210, duckdb#28134, duckdb#28222, duckdb#28231, duckdb#28232, duckdb#28235, duckdb#28239,
duckdb#28241, duckdb#28019, duckdb#28199, duckdb#28230, duckdb#28188, duckdb#28246, duckdb#28245, duckdb#28228, duckdb#28251,
duckdb#27852, duckdb#28223, duckdb#28252, duckdb#28258, duckdb#28253, duckdb#28180, duckdb#27779.

## Not included

These depend on changes that are not on this branch:

- duckdb#27943: needs 321ded7 (constant and dictionary vectors in
`ColumnDataCollection`).
- duckdb#27999: needs index-key collation, TRY-subquery binder state and
update-segment changes.
- duckdb#27326: needs 32cb90d (Parquet Thrift metadata arena).
- duckdb#28225: needs the TRY lowering (`ExpressionType::OPERATOR_HAS_ERROR`).
- duckdb#27849: the regenerated parser trampolines did not build on this
branch.

## Notes

- duckdb#28119 and duckdb#28120 report the same merge commit in the GitHub API,
duckdb#28120 is picked from its own commit.
- Dropped test hunks and files that belong to features not on this
branch (duckdb#28029, duckdb#27998, duckdb#28076, duckdb#28188, duckdb#28056, duckdb#27767, duckdb#27804).
- Built `reldebug` and ran all added or changed `.test` files: all pass.
The full suite was not run.

- Release-only change, not a backport: `round` in
`extension/core_functions/scalar/math/numeric.cpp` now rounds half away
from zero without calling the platform `round` (MinGW rounds
`0.49999999999999994` to `1`). `main` still uses `std::round`; the same
fix is open in duckdb#28306 and duckdb#28307, so it should be backported once one of
them merges.
- Release-only change, not a backport: the 256 MB and 512 MB `SELECT 42`
cases in `tools/shell/tests/test_address_space_limit.py` are skipped
because they segfault on v2.0-cyanoptera after running out of address
space at startup. Whether the fix in duckdb#28310 can be backported to
re-enable them is still to be checked.