Introduce `raft` experimental option.
Adjust the tests accordingly to accomodate the new option.
It's not enabled by default when providing
`--experimental=true` config option and should be
requested explicitly via `--experimental-options=raft`
config option.
Hide the code related to `raft_group_registry` behind
the switch. The service object is still constructed
but no initialization is performed (`init()` is not
called) if the flag is not set.
Later, other raft-related things, such as raft schema
changes, will also use this flag.
Also, don't introduce a corresponding gossiper feature
just yet, because again, it should be done after the
raft schema changes API contract is stabilized.
This will be done in a separate series, probably related to
implementing the feature itself.
Tests: unit(dev)
Ref #9239.
Signed-off-by: Pavel Solodovnikov <pa.solodovnikov@scylladb.com>
Message-Id: <20210823121956.167682-1-pa.solodovnikov@scylladb.com>
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