* Support ! modifier (same as '-')
* Create reusable PopupHelpWidget as self-contained popup that can
be positioned around a parent widget and will follow the movement
and sizing of the window
* Eliminated KEEPASSXC_MAIN_WINDOW macro and replaced with
getMainWindow() function
* Add tests to cover search help show/hide
This patch aims at reducing the number of copies for obejcts that could
be referenced rather than copied, because they're not modified during
the computation.
* Search Group details in addition to entry details; feature parity with KeePass
* Remove assertions to prevent crashes in Debug mode when search result is empty