This patch adds the snapshot_sstables table with the following
schema:
```cql
CREATE TABLE system_distributed.snapshot_sstables (
snapshot_name text,
keyspace text, table text,
datacenter text, rack text,
id uuid,
first_token bigint, last_token bigint,
toc_name text, prefix text)
PRIMARY KEY ((snapshot_name, keyspace, table, datacenter, rack), first_token, id);
```
The table will be populated by the coordinator node during the restore
phase (and later on during the backup phase to accomodate live-restore).
The content of this table is meant to be consumed by the restore worker nodes
which will use this data to filter and file-based download sstables.
Fixes SCYLLADB-263
Signed-off-by: Robert Bindar <robert.bindar@scylladb.com>
daa09abc2a