storcon_cli: add support for drain and fill operations (#8791)

## Problem
We have been naughty and curl-ed storcon to fix-up drains and fills.

## Summary of changes
Add support for starting/cancelling drain/fill operations via
`storcon_cli`.

storage_controller/src/http.rs

@@ -1074,7 +1074,6 @@ pub fn make_router(
                 RequestName("control_v1_metadata_health_list_outdated"),
             )
         })
-        // TODO(vlad): endpoint for cancelling drain and fill
         // Tenant Shard operations
         .put("/control/v1/tenant/:tenant_shard_id/migrate", |r| {
             tenant_service_handler(