Feature: Integrate ace editor for templates

[iampearceman]

🔖 Feature description

The variables at the right side are okay, but it would be better to have a code editor with intellisense / autocompletion and proper syntax highlighting.

🎤 Why is this feature needed ?

Find errors in templates before you save them.

✌️ How do you aim to achieve this?

1. Add ace editor.
2. Create a model of all variables
3. Provide intellisense.

🔄️ Additional Information

No response

👀 Have you spent some time to check if this feature request has been raised before?

• I checked and didn't find similar issue

🏢 Have you read the Code of Conduct?

• I have read the Contributing Guidelines

Are you willing to submit PR?

None

_NV-1652