In this PR a simple test for fencing is added. It exercises the data
plane, meaning if it somehow happens that the node has a stale topology
version, then requests from this node will get an error 'stale
topology'. The test just decrements the node version manually through
CQL, so it's quite artificial. To test a more real-world scenario we
need to allow the topology change fiber to sometimes skip unavailable
nodes. Now the algorithm fails and retries indefinitely in this case.
The PR also adds some logs, and removes one seemingly redundant topology
version increment, see the commit messages for details.
Closes#14901
* github.com:scylladb/scylladb:
test_fencing: add test_fence_hints
test.py: output the skipped tests
test.py: add skip_mode decorator and fixture
test.py: add mode fixture
hints: add debug log for dropped hints
hints: send_one_hint: extend the scope of file_send_gate holder
pylib: add ScyllaMetrics
hints manager: add send_errors counter
token_metadata: add debug logs
fencing: add simple data plane test
random_tables.py: add counter column type
raft topology: don't increment version when transitioning to node_state::normal
cdc3cd2b79