Merge pull request #42901 from athanatos/sjust/wip-lba-rewrite

crimson/os/seastore: replace lba btree implementation with simpler, more correct iterator based implementation

Reviewed-by: Chunmei Liu <chunmei.liu@intel.com>
Reviewed-by: Yingxin Cheng <yingxin.cheng@intel.com>

diff --cc src/crimson/os/seastore/cache.cc
Simple merge

diff --cc src/crimson/os/seastore/cache.h
Simple merge