Make tool calls more robust regarding invalid JSON

[xai]

Bug Description:

I sometimes run into these kind of issues during tool calls:

Running changeSet_replaceContentInFile(...{"path": "packages/ai-core/src/browser/platform-compatibility.spec.ts", "replacements":[{"oldContent": " static requestPermission = (): Promise<NotificationPermission> => Promise.resolve('granted');\n \n constructor(title: string, options?: NotificationOptions) {", "newContent": " static requestPermission = (): Promise<NotificationPermission> => Promise.resolve('granted');\n\n constructor(title: string, options?: NotificationOptions) {"}]</parameter> </invoke>":)
Expected ',' or '}' after property value in JSON at position 512 (line 1 column 513)

This results in an error, stopped execution of the agent and potentially lost progress.

Steps to Reproduce:

no idea

Additional Information

• Operating System: Linux
• Theia Version: 1.62.0