feat(amazonq): Adding diff view UX for generated files in Agentic chat (#6876)

## Problem
- Existing UX accepts the generated files without permission check.

## Solution
- Added code diff view using VSC native diff functionality, Users can
click on the generated files and see the code diff.
- Users can now accept/reject the generated code.
- Close the diff view once user clicks on Accept or Reject.
- Fix: If user clicks on `Confirm` button to execute the bash command
change this to `Confirmed` state.
- In read tool execution and safe bash command execution use different
id: `generic-tool-execution` in processCustomFormAction as this helps
the above step to execute.
- Fix: Removing the Q spinner component if user clicks on reject button
or code diff filePath.



https://github.com/user-attachments/assets/be672101-aed4-4fa7-95d7-6a932d0f95ac



---

- Treat all work as PUBLIC. Private `feature/x` branches will not be
squash-merged at release time.
- Your code changes must meet the guidelines in
[CONTRIBUTING.md](https://github.com/aws/aws-toolkit-vscode/blob/master/CONTRIBUTING.md#guidelines).
- License: I confirm that my contribution is made under the terms of the
Apache 2.0 license.

Author: laileni-aws

packages/core/src/amazonq/webview/ui/apps/cwChatConnector.ts

@@ -264,7 +264,10 @@ export class Connector extends BaseConnector {
             tabID: tabId,
         })
 
-        if (!this.onChatAnswerUpdated || !['accept-code-diff', 'reject-code-diff'].includes(action.id)) {
+        if (
+            !this.onChatAnswerUpdated ||
+            !['accept-code-diff', 'reject-code-diff', 'confirm-tool-use'].includes(action.id)
+        ) {
             return
         }
         const answer: ChatItem = {
@@ -297,6 +300,18 @@ export class Connector extends BaseConnector {
                     },
                 ]
                 break
+            case 'confirm-tool-use':
+                answer.buttons = [
+                    {
+                        keepCardAfterClick: true,
+                        text: 'Confirmed',
+                        id: 'confirmed-tool-use',
+                        status: 'success',
+                        position: 'outside',
+                        disabled: true,
+                    },
+                ]
+                break
             default:
                 break
         }

packages/core/src/codewhispererChat/clients/chat/v0/chat.ts

@@ -19,13 +19,9 @@ export class ChatSession {
     private sessionId?: string
     /**
      * _readFiles = list of files read from the project to gather context before generating response.
-     * _filePath = The path helps the system locate exactly where to make the necessary changes in the project structure
-     * _tempFilePath = Used to show the code diff view in the editor including LLM changes.
      * _showDiffOnFileWrite = Controls whether to show diff view (true) or file context view (false) to the user
      */
     private _readFiles: string[] = []
-    private _filePath: string | undefined
-    private _tempFilePath: string | undefined
     private _toolUse: ToolUse | undefined
     private _showDiffOnFileWrite: boolean = false
 
@@ -61,24 +57,12 @@ export class ChatSession {
     public get readFiles(): string[] {
         return this._readFiles
     }
-    public get filePath(): string | undefined {
-        return this._filePath
-    }
-    public get tempFilePath(): string | undefined {
-        return this._tempFilePath
-    }
     public get showDiffOnFileWrite(): boolean {
         return this._showDiffOnFileWrite
     }
     public setShowDiffOnFileWrite(value: boolean) {
         this._showDiffOnFileWrite = value
     }
-    public setFilePath(filePath: string | undefined) {
-        this._filePath = filePath
-    }
-    public setTempFilePath(tempFilePath: string | undefined) {
-        this._tempFilePath = tempFilePath
-    }
     public addToReadFiles(filePath: string) {
         this._readFiles.push(filePath)
     }