This is because we only check if the last message component != Text,
because that handles it's own edit strings. Quote components do that
too, so if we don't exclude it there ends up being two (edited) strings
in one message.
This was a mistake in the code that was designed to remove the outside
paragraphs, which seems to be to make way for the quotation marks we
add around the text. Instead of doing that (which turns out, is very
brittle and breaks on multiple paragraphs) insert the quotation marks
*inside* of the paragraph tags.
A test case is added for this as well.
Make `DelegateSizeHelper` take a `QQuickItem` rather than a width value and move `TimelineDelegate` to use it rather than duplicting the code.
This requires the creation of `LibNeoChat` so that both the main and timeline modules can get access to the class.
Note: ideally more stuff will go into `LibNeoChat` but it turns out our dependencies are kinda spaghetti like and so will take some untangling.
