Clean up code that became redundant through framework changes
There were two changes in framework that triggered this commit: KHamburgerMenu and KToolTipHelper. When the Dolphin-specific hamburger menu was replaced by KHamburgerMenu, I didn't clean everything up correctly. Not anymore! Help texts also weren't updated accordingly. This commit replaces any mention of the old hamburger menu which was called "Control" with text that reflects the current application state. The other framework change "KToolTipHelper" takes responsibility for opening links in help texts. So we won't need code to do this in Dolphin anymore. This means we can also get rid of some duplicate help texts which only existed because links didn't work correctly in some places.