As requested in #22102, #22103 and #22105 moved the files and fixed other includes and build system.
Moved files:
- clustering_bounds_comparator.hh
- keys.cc
- keys.hh
- clustering_interval_set.hh
- clustering_key_filter.hh
- clustering_ranges_walker.hh
- compound_compat.hh
- compound.hh
- full_position.hh
Fixes: #22102Fixes: #22103Fixes: #22105Closesscylladb/scylladb#25082
While generally better to reduce inline code, here we get
rid of the clustering_interval_set.hh dependency, which in turns
depends on boost interval_set, a large dependency.
incremental_compaction_test.cc is adjusted for a missing header.
Closesscylladb/scylladb#22957