feat(ai): Add toolbar actions for chat nodes

[planger]

What it does

Introduces a ChatNodeToolbarActionContribution which allows to add icons to the chat nodes in the Chat UI on hover. Clicking these icons will trigger a command that gets the respective chat node as argument.

Possible use cases are actions for reporting the content, giving feedback, or perform other actions within the tool based on the response.

Contributed on behalf of STMicroelectronics.

How to test

Add a ChatNodeToolbarActionContribution to a frontend module:

bind(ChatNodeToolbarActionContribution).toDynamicValue(context => ({
 getToolbarActions: (args: RequestNode | ResponseNode) => {
     if (isResponseNode(args)) {
         return [{
             commandId: 'core.about',
             icon: 'codicon codicon-feedback',
             tooltip: 'Show about dialog on response nodes'
         }];
     } else {
         return [];
     }
 }

Then trigger a chat and check whether the action appears on hover.

Follow-ups

N/A

Review checklist

• As an author, I have thoroughly tested my changes and carefully followed the review guidelines

Reminder for reviewers

• As a reviewer, I agree to behave in accordance with the review guidelines

[sdirix]

Works for me!

I tested with multiple contributions including different priorities and the toolbar was rendered as expected.

I wonder whether we should add an example to the official Theia examples. Maybe with the hello world command instead of about.

[planger]

@sdirix Thanks for the review!

Good idea regarding the example. I added a chat node action contribution. I used the about command, however, as I didn't find a better suited command defined in the examples. Please let me know what you think.