Lazy loading of messages

Currently, all messages are loaded at once. With chat histories becoming bigger and bigger, this could result in serious performance problems.

Related issue in wrapper: python-briar-wrapper#5

added T: task label

mentioned in issue python-briar-wrapper#5

changed the description

changed milestone to %GTK Next

I think the problem here is not so much the network request, since that's all local. Instead, GTK seems to have a problem with big lists:

As a rule of thumb, GtkListBox can handle 1 000 items well

https://blog.gtk.org/2020/06/07/scalable-lists-in-gtk-4/

This seems to might get improved in GTK 4 with other GTK widgets, so we might not do anything as of now.

removed milestone

mentioned in issue #80

added S: diagnosed Usability labels

This will be fixed "automatically" as part of #80.

added S: blocked label

Actually, #80 isn't really about lazy loading but still will fix this issue, although with a different solution.

closed

mentioned in issue #91