In order to support different storage kinds for sstable files (e.g. -- s3) it's needed to localize all the places that manipulate files on a POSIX filesystem so that custom storage could implement them in its own way. This set moves the deletion log manipulations to the sstable_directory.cc, which already "knows" that it works over a directory.
Closes#12020
* github.com:scylladb/scylladb:
sstables: Delete log file in replay_pending_delete_log()
sstables: Move deletion log manipulations to sstable_directory.cc
sstables: Open-code delete_sstables() call
sstables: Use fs::path in replay_pending_delete_log()
sstables: Indentation fix after previous patch
sstables: Coroutinize replay_pending_delete_log
sstables: Read pending delete log with one line helper
sstables: Dont write pending log with file_writer
bf2e54ff85