feat(dev): include in progress state agent details in code generation (#5489)

## Problem

Currently we display a long-running message "Generating code ... " while
in code generation still IN_PROGRESS state. There is an often customer
feedback based on this experience that its "stuck" or not "progressing".

Although the RTS and LLM are processing the request, user expects some
feedback on whats is doing or if its actually stuck processing.

## Solution

This PR provides exposure for the codeGenerationStatusDetail which will
be leveraged to return the strings in the following format:

LLM actions example returned:

"I have reviewed 7 files and applied changes to 3 files in total so far.

Most recently, I reviewed 2 files and applied changes to 1 file. "

Error scenario while IN_PROGRESS:

"The previous attempt failed. I am retrying now. For reference, the
previous
attempt took approximately 1 minute and involved 3 files."

Author: tverney

packages/amazonq/.changes/next-release/Feature-0da66e82-7f81-46c7-be39-5634cf0a64f3.json

@@ -0,0 +1,4 @@
+{
+	"type": "Feature",
+	"description": "Amazon Q /dev: include in progress state agent in code generation"
+}

packages/core/src/amazonqFeatureDev/session/sessionState.ts

@@ -43,6 +43,7 @@ import { AuthUtil } from '../../codewhisperer/util/authUtil'
 import { randomUUID } from '../../shared/crypto'
 import { collectFiles, getWorkspaceFoldersByPrefixes } from '../../shared/utilities/workspaceUtils'
 import { i18n } from '../../shared/i18n-helper'
+import { Messenger } from '../controllers/chat/messenger/messenger'
 
 export class ConversationNotStartedState implements Omit<SessionState, 'uploadId'> {
     public tokenSource: vscode.CancellationTokenSource
@@ -245,11 +246,13 @@ abstract class CodeGenBase {
     }
 
     async generateCode({
+        messenger,
         fs,
         codeGenerationId,
         telemetry: telemetry,
         workspaceFolders,
     }: {
+        messenger: Messenger
         fs: VirtualFileSystem
         codeGenerationId: string
         telemetry: TelemetryHelper
@@ -278,6 +281,7 @@ abstract class CodeGenBase {
                         await this.config.proxyClient.exportResultArchive(this.conversationId)
                     const newFileInfo = registerNewFiles(fs, newFileContents, this.uploadId, workspaceFolders)
                     telemetry.setNumberOfFilesGenerated(newFileInfo.length)
+
                     return {
                         newFiles: newFileInfo,
                         deletedFiles: getDeletedFileInfos(deletedFiles, workspaceFolders),
@@ -288,6 +292,15 @@ abstract class CodeGenBase {
                 }
                 case CodeGenerationStatus.PREDICT_READY:
                 case CodeGenerationStatus.IN_PROGRESS: {
+                    if (codegenResult.codeGenerationStatusDetail) {
+                        messenger.sendAnswer({
+                            message:
+                                i18n('AWS.amazonq.featureDev.pillText.generatingCode') +
+                                `\n\n${codegenResult.codeGenerationStatusDetail}`,
+                            type: 'answer-part',
+                            tabID: this.tabID,
+                        })
+                    }
                     await new Promise((f) => globals.clock.setTimeout(f, this.requestDelay))
                     break
                 }
@@ -381,11 +394,13 @@ export class CodeGenState extends CodeGenBase implements SessionState {
                 })
 
                 const codeGeneration = await this.generateCode({
+                    messenger: action.messenger,
                     fs: action.fs,
                     codeGenerationId,
                     telemetry: action.telemetry,
                     workspaceFolders: this.config.workspaceFolders,
                 })
+
                 this.filePaths = codeGeneration.newFiles
                 this.deletedFiles = codeGeneration.deletedFiles
                 this.references = codeGeneration.references