Ref: #7617
This series adds timeout parameters to service levels.
Per-service-level timeouts can be set up in the form of service level parameters, which can in turn be attached to roles. Setting up and modifying role-specific timeouts can be achieved like this:
```cql
CREATE SERVICE LEVEL sl2 WITH read_timeout = 500ms AND write_timeout = 200ms AND cas_timeout = 2s;
ATTACH SERVICE LEVEL sl2 TO cassandra;
ALTER SERVICE LEVEL sl2 WITH write_timeout = null;
```
Per-service-level timeouts take precedence over default timeout values from scylla.yaml, but can still be overridden for a specific query by per-query timeouts (e.g. `SELECT * from t USING TIMEOUT 50ms`).
Closes#7913
* github.com:scylladb/scylla:
docs: add a paragraph describing service level timeouts
test: add per-service-level timeout tests
test: add refreshing client state
transport: add updating per-service-level params
client_state: allow updating per service level params
qos: allow returning combined service level options
qos: add a way of merging service level options
cql3: add preserving default values for per-sl timeouts
qos: make getting service level public
qos: make finding service level public
treewide: remove service level controller from query state
treewide: propagate service level to client state
sstables: disambiguate boost::find
cql3: add a timeout column to LIST SERVICE LEVEL statement
db: add extracting service level info via CQL
types: add a missing translation for cql_duration
cql3: allow unsetting service level timeouts
cql3: add validating service level timeout values
db: add setting service level params via system_distributed
cql3: add fetching service level attrs in ALTER and CREATE
cql3: add timeout to service level params
qos: add timeout to service level info
db,sys_dist_ks: add timeout to the service level table
migration_manager: allow table updates with timestamp
cql3: allow a null keyword for CQL properties
61c7f874cc