* Introduce crossPlatformCopy()
It sets the text of the clipboard and also syncs it with the selection
clipboard if it is supported. Such behaviour is pretty common for X11
application on Unix-like Operating Systems.
* Fix clang-format remarks
* Fix weird clang-format config discrepancy between my machine and CI
* Remove clipboard argument from crossPlatformCopy
* Fix clang-format remarks
Supa quick fix for #1100
Looks like this bug may come back in other places where we use
`TooltipWidget`. For a permanent fix we have to go through all of the
places that touch `TooltipWidget` and check if they clean the preview
image correctly.
It would be better to merge TooltipPreviewImage and TooltipWidget
together and change `TooltipWidget::setText` to be
```c++
void TooltipWidget::setText(const QString &text, ImagePtr image = ptrnull);
```
But it's impossible right now, because TooltipWidget is located in
appbase and `ImagePtr` is not visible there (it's located in the main
chatterino repo). Plus we also need an access to
`getApp()->windows->gifRepaintRequested`.
First step in implementing the permanent fix would be moving
TooltipWidget to chatterino from appbase.
Any thoughts on the situation?
Alexey Kutepovandfourtf
