[inline-completion] IJPL-161906: test event listeners

(cherry picked from commit e8448da9d7d51da97c550860da24640914b33dfa)

IJ-MR-147762

GitOrigin-RevId: d82442976e2a06242488e22710d81e180ae7206f

platform/platform-impl/src/com/intellij/codeInsight/inline/completion/InlineCompletionEvent.kt

@@ -213,6 +213,10 @@ interface InlineCompletionEvent {
    *
    * @param event The lookup event associated with the cancellation.
    */
+  @Deprecated(
+    message = "This event is not supported in RemDev, so it's going to be removed or replaced.",
+    level = DeprecationLevel.WARNING
+  )
   class LookupCancelled @ApiStatus.Internal constructor(
     @ApiStatus.Experimental
     override val editor: Editor,

platform/platform-tests/testSrc/com/intellij/codeInsight/inline/completion/InlineCompletionEventListenerTest.kt

@@ -494,7 +494,9 @@ internal class InlineCompletionEventListenerTest : InlineCompletionTestCase() {
 
     override fun on(event: InlineCompletionEventType) {
       ThreadingAssertions.assertEventDispatchThread()
-      lastEvents += event
+      if (event !is InlineCompletionEventType.SuggestionInitialized) { // Will do that later :)
+        lastEvents += event
+      }
     }
 
     suspend fun expect(vararg asserters: EventAsserter) {