fix: [Amazon Q] handle exceptions in service request (#4140)

Currently, most exceptions that occur when the amazon Q API is invoked
are suppressed and are not surfaced to the user (For ex,
`AccessDeniedException`).

The plugin proceeds like the call succeeded, and subsequently makes another
call to add a telemetry event that also fails due to an improperly formed
request (from not having a conversationId), and the user is shown this error
instead of the original error.

This change fixed that.

Author: AnirudhKonduru

.changes/next-release/bugfix-2f848e2b-d35e-40a9-a89e-59e5bb8df212.json

@@ -0,0 +1,4 @@
+{
+  "type" : "bugfix",
+  "description" : "Amazon Q: Service exceptions are not suppressed and displayed to the user."
+}

jetbrains-core/src/software/aws/toolkits/jetbrains/services/cwc/controller/chat/messenger/ChatPromptHandler.kt

@@ -52,6 +52,9 @@ class ChatPromptHandler(private val telemetryHelper: TelemetryHelper) {
                 // Don't emit any other responses if we cancelled the collection
                 if (error is CancellationException) {
                     return@onCompletion
+                } // for any other exception, let the `catch` operator handle it.
+                else if (error != null) {
+                    throw error
                 }
 
                 // Send the gathered suggestions in a final answer-part message