Snapshot-ctl methods fetch information about snapshots from
column family objects. The problem with this is that we get rid
of these objects once the table gets dropped, while the snapshots
might still be present (the auto_snapshot option is specifically
made to create this kind of situation). This commit switches from
relying on column family interface to scanning every datadir
that the database knows of in search for "snapshots" folders.
This PR is a rebased version of #9539 (and slightly cleaned-up, cosmetically)
and so it replaces the previous PR.
Fixes#3463Closes#7122Closes#9884
* github.com:scylladb/scylla:
snapshots: Fix snapshot-ctl to include snapshots of dropped tables
table: snapshot: add debug messages