SQL Expressions: Make SQL Expressions work with Alerting (#101820)

Initial support for alerting with SQL expressions

- When `format` is set to `alerting`, SQL expressions output in a format suitable for alerting evaluation.
- Outstanding TODOs:
  - Deduplicate output rows
  - Add more tests
  - Fix broken alerting UI rendering (likely due to shape change to undocumented full-long format)
- Basic usage:
  - SQL must return one numeric column and one or more string columns.
  - Each row may become an alert.
  - The alert fires if the numeric value is non-zero.
  - String columns are treated as labels.

---------

Co-authored-by: Konrad Lalik <konradlalik@gmail.com>
Co-authored-by: Tom Ratcliffe <tom.ratcliffe@grafana.com>
Co-authored-by: Sam Jewell <sam.jewell@grafana.com>

pkg/expr/query.types.json

@@ -552,7 +552,7 @@
     {
       "metadata": {
         "name": "sql",
-        "resourceVersion": "1709915973363",
+        "resourceVersion": "1743431268321",
         "creationTimestamp": "2024-02-29T00:58:00Z"
       },
       "spec": {
@@ -573,10 +573,14 @@
               ],
               "minLength": 1,
               "type": "string"
+            },
+            "format": {
+              "type": "string"
             }
           },
           "required": [
-            "expression"
+            "expression",
+            "format"
           ],
           "type": "object"
         },
@@ -584,11 +588,12 @@
           {
             "name": "Select the first row from A",
             "saveModel": {
-              "expression": "SELECT * FROM A limit 1"
+              "expression": "SELECT * FROM A limit 1",
+              "format": ""
             }
           }
         ]
       }
     }
   ]
-}
+}