Implement message attachments

[brichet]

Description

• Implements new methods for adding, removing, and viewing message attachments.
• Fixes Design a way to attach JSON objects to messages #147.

Demo

record-2025-02-13_11.04.21.webm

There is now a lite deployment in the built doc including a simple extension with a chat panel. I updated it to allow attachments https://jupyter-chat--148.org.readthedocs.build/en/148/lite/lab/index.html

[github-actions]

👈 Launch a Binder on branch brichet/jupyter-chat/message_attachments

[dlqqq]

@brichet Thank you for working on this while I was away! Left some feedback below.

[brichet]

Thanks for the review @dlqqq, I addressed some of your comments. I'll take a look at an alternative to clickAttachments().

[brichet]

The recurrent failing test do not fails locally. And strangely, it constantly fails at opening the chat, which is done in other tests with the same chat file...

[brichet]

The recurrent failing test do not fails locally. And strangely, it constantly fails at opening the chat, which is done in other tests with the same chat file...

The failing test is the first one of the notification tests. After reordering the tests, the 'new' first test is now failing.
I'll try to fix it, otherwise we would have to disable the whole test group.

[brichet]

I finally skipped the notification test for now, I'll open a issue when this PR is merged to restore it in a follow up PR.

[dlqqq]

Thank you @brichet, the new changes look great! Left some additional minor feedback.

[dlqqq]

I'll approve this PR because my latest feedback is minor & non-blocking.

If you do merge, please open follow-up issues for my latest feedback, thank you!