Feature request: Multi Attachment Support

[alexrisch]

Is your feature request related to a problem?

Add support for sending Multiple Attachments at once

Composer UI: https://www.figma.com/design/PUfpkzt9dFX5GR1U1Fw3mQ/Converse-Global-Styles?node-id=474-11544&t=A3S3iVwmVOrlsaah-1

Will want to have multi attachment Message View Figma

We will wait for a protocol level content type

Describe the solution to the problem

No response

Describe the uses cases for the feature

No response

Additional details

No response

[covrter]

Opening thoughts here:

• what kind of attachments do we support, in general?
• IMO multi-attachment display in the chat can be scoped to photo attachments only
  • so even if I put 2 videos in the composer, that can get sent as 2 messages
  • but if I put 2-N pics in the composer, that's 1 message (with a unique UI that "stacks" them)
• Messenger handles this nicely (good patterns to follow)
• Fallback treatment could be WhatsApp (multi-send but no unique UI for it)

Media viewer needs love too:

• Media gallery view (fullscreen pic/video), swipe between