[libc++] Refactor and add benchmark coverage for [alg.sort] (#128236)

This patch adds missing benchmark coverage for partial_sort,
partial_sort_copy, is_sorted and is_sorted_until.

It also refactors the existing benchmarks for sort and stable_sort to
follow the consistent style of the new algorithm benchmarks. However,
these benchmarks were notoriously slow to run since they tested multiple
data patterns on multiple data types. To try to alleviate this, I
reduced the benchmarks to only run on integral types and on a single
non-integral type, which should faithfully show how the algorithm
behaves for anything non-integral. However, this is technically a
reduction in coverage.

0 files changed, 0 insertions, 0 deletions