feat(coderd): insert provisioner daemons (#11207)

* Adds UpdateProvisionerDaemonLastSeenAt
* Adds heartbeat to provisioner daemons
* Inserts provisioner daemons to database upon start
* Ensures TagOwner is an empty string and not nil
* Adds COALESCE() in idx_provisioner_daemons_name_owner_key

cli/testdata/coder_list_--output_json.golden

@@ -36,6 +36,7 @@
         "worker_id": "[workspace build worker ID]",
         "file_id": "[workspace build file ID]",
         "tags": {
+          "owner": "",
           "scope": "organization"
         },
         "queue_position": 0,