When users create a table using the Alternator API, they can decide if the billing is PROVISIONED of PAY_PER_REQUEST.
If the billing is set to PROVISIONED, they need to set the ProvisionedThroughput ReadCapacityUnits (RCU) and WriteCapacityUnits (WCU).
This series adds support for getting and setting the ProvisionedThroughput. The values will be stored as table extension tags.
Following how TTL is stored within the Alternator, we will use ```system:rcu_attribute``` and ```system:wcu_attribute``` for the labels.
The series adds a test that sets ProvisionedThroughput and validates that it gets the value back. It was tested with both Alternator and AWS.
This series is part of the effort to monitor, limit, and bill Alternator operations.
New code, no need to backport.
Closesscylladb/scylladb#20056
* github.com:scylladb/scylladb:
docs/alternator/compatibility.md: explain the consumed capacity provisioned
Add test/alternator/test_provisioned_throughput.py
test/alternator/util.py: Allow override BillingMode
alternator/executor.cc: Store ProvisionedThroughput