Hotkeys: change default setting: GoToParent (Alt+P, instead of Ctrl+C), GoToChild (Alt+C, instead of Ctrl+C)

This makes the key settings more consistent to the Next/PrevQuickSearch which also use Alt as modifier. And it makes Ctrl+C free for more intuitive operation: copy to clipboard.
default key setting for ToggleHighlightSelectedBranch: Ctrl+Shift+B
Hotkeys: use Ctrl+C to copy commit hash to clipboard
Hotkeys: change default setting: GoToParent (Ctrl+P), GoToChild (Ctrl+N (= next))
Merge pull request #1865 from feinstaub/feature/keyboardshortcut_Ctrl_C

Hotkeys: use Ctrl+C to copy commit hash to clipboard