Following up on 69aea59d97, which added fencing support
for simple reads and writes, this series does the same for the
complex ops:
- partition scan
- counter mutation
- paxos
With this done, the coordinator knows about all in-flight requests and
can delay topology changes until they are retired.
Closes#11296
* github.com:scylladb/scylladb:
storage_proxy: hold effective_replication_map for the duration of a paxos transaction
storage_proxy: move paxos_response_handler class to .cc file
storage_proxy: deinline paxos_response_handler constructor/destructor
storage_proxy: use consistent effective_replication_map for counter coordinator
storage_proxy: improve consistency in query_partition_key_range{,_concurrent}
storage_proxy: query_partition_key_range_concurrent: reduce smart pointer use
storage_proxy: query_partition_key_range_concurrent: improve token_metadata consistency
storage_proxy: query_singular: use fewer smart pointers
storage_proxy: query_singular: simplify lambda captures
locator: effective_replication_map: provide non-smart-pointer accessor to token_metadata
storage_proxy: use consistent token_metadata with rest of singular read
87b7e7ff9c