telemetry(amazonq): add fields for SQL conversions (#891)

## Problem

Need telemetry for our upcoming feature which performs SQL conversions.

## Solution

Add source and target DBs allowed to an existing `submitSelection`
metric.

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## License

By submitting this pull request, I confirm that my contribution is made
under the terms of the Apache 2.0 license.

---------

Co-authored-by: David Hasani <[email protected]>

Author: dhasani23

telemetry/definitions/commonDefinitions.json

@@ -1681,6 +1681,11 @@
                 "CodeOnly"
             ]
         },
+        {
+            "name": "target",
+            "type": "string",
+            "description": "The target of the operation"
+        },
         {
             "name": "templateName",
             "type": "string",
@@ -4059,6 +4064,14 @@
                     "type": "result",
                     "required": true
                 },
+                {
+                    "type": "source",
+                    "required": false
+                },
+                {
+                    "type": "target",
+                    "required": false
+                },
                 {
                     "type": "userChoice",
                     "required": false