Fix creation of prompts not opening files in the editor (#5781)

There was a threading issue where since the file was opened in EDT and the result was sent back to the server on another thread, it returned the result before the file was opened. This PR makes it synchronous

Author: manodnyab

plugins/amazonq/shared/jetbrains-community/src/software/aws/toolkits/jetbrains/services/amazonq/lsp/AmazonQLanguageClientImpl.kt

@@ -158,18 +158,21 @@ class AmazonQLanguageClientImpl(private val project: Project) : AmazonQLanguageC
             // The filepath sent by the server contains unicode characters which need to be
             // decoded for JB file handling APIs to be handle to handle file operations
             val fileToOpen = URLDecoder.decode(params.uri, StandardCharsets.UTF_8.name())
-            ApplicationManager.getApplication().invokeLater {
-                try {
-                    val virtualFile = VirtualFileManager.getInstance().findFileByUrl(fileToOpen)
-                        ?: throw IllegalArgumentException("Cannot find file: $fileToOpen")
-
-                    FileEditorManager.getInstance(project).openFile(virtualFile, true)
-                } catch (e: Exception) {
-                    LOG.warn { "Failed to show document: $fileToOpen" }
-                }
-            }
+            return CompletableFuture.supplyAsync(
+                {
+                    try {
+                        val virtualFile = VirtualFileManager.getInstance().refreshAndFindFileByUrl(fileToOpen)
+                            ?: throw IllegalArgumentException("Cannot find file: $fileToOpen")
 
-            return CompletableFuture.completedFuture(ShowDocumentResult(true))
+                        FileEditorManager.getInstance(project).openFile(virtualFile, true)
+                        ShowDocumentResult(true)
+                    } catch (e: Exception) {
+                        LOG.warn { "Failed to show document: $fileToOpen" }
+                        ShowDocumentResult(false)
+                    }
+                },
+                ApplicationManager.getApplication()::invokeLater
+            )
         } catch (e: Exception) {
             LOG.warn { "Error showing document" }
             return CompletableFuture.completedFuture(ShowDocumentResult(false))