Merge pull request #47816 from cyx1231st/wip-seastore-split-trimmer

crimson/os/seastore/async_cleaner: factor out journal trimming implementation

Reviewed-by: Myoungwon Oh <myoungwon.oh@samsung.com>
Reviewed-by: Xuehan Xu <xxhdx1985126@gmail.com>
Reviewed-by: Zhang Song <zhangsong325@gmail.com>
Reviewed-by: Samuel Just <sjust@redhat.com>

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