This move the finding of links and the creation of a `linkpreviewer` into c++.
- The links are now extracted from the text in `texthandler`
- The `messageeventmodel` now creates and stores `linkpreviewers` for events that have links in the current room.
Two new model roles have been created to let a text delegate know when the link preview should be shown (`showLinkPreview`) and pass the link previewer (`linkPreviewer`). Empty link previewer are returned where link don't exist so the qml doesn't have to have checks for whether the parameters are undefined.
- Add the ability to set the deafult url preview setting for the room if you have sufficient power level.
- Add the ability for the user to set the desired url preview setting.
network/neochat#560
Update linkpreviewer to minimise the number of resizes.
- There is now a placeholder loading element to hold space while the data is obtained
- The component starts with a set size but can be expanded to see the whole item.
- The expand/contract button is only visible on hover
- The default size is picked to show 3 lines of text (1 heading and 2 description, 2 heading and 1 description, etc)
This is designed to help with the timeline scroll jumping CCBUG: 463235 by minimizing the amount of resizing for items in the timeline.
Before
After when compressed
After When expanded
After Loading
