`close()` is a virtual function. Since we are calling it from a
destructor, make it clear that we are specifically calling the base
class (`QIODevice`) implementation, as opposed to an implementation in
any derived class.
[Found by lgtm.com](https://lgtm.com/projects/g/keepassxreboot/keepassxc/alerts)
Many lines were not conformant with the project's formatting rules.
This patch should fix all formatting and whitespace issues in the code
base.
A clang-format directive was put around the connect() calls containing
SIGNALs and SLOTs whose signatures would be denormalized because of the
formatting rules.
