[preferences][keybinding] Duplicate keybinding for opening the preferences widget

[kittaakos]

Bug Description:

On macOS, there should be one keybinding for opening the preferences widget: Cmd+,. Currently, both Cmd and Ctrl work on macOS:

theia/packages/preferences/src/browser/preference-contribution.ts

Lines 133 to 143 in ac06ac9

	if (isOSX && !isFirefox) {
	keybindings.registerKeybinding({
	command: CommonCommands.OPEN_PREFERENCES.id,
	keybinding: 'cmd+,'
	});
	}
	keybindings.registerKeybinding({
	command: CommonCommands.OPEN_PREFERENCES.id,
	keybinding: 'ctrl+,',
	});

Steps to Reproduce:

Additional Information

• Operating System:
• Theia Version:

[kittaakos]

Same for Delete:

theia/packages/navigator/src/browser/navigator-contribution.ts

Lines 443 to 454 in 4c63f08

	registry.registerKeybinding({
	command: WorkspaceCommands.FILE_DELETE.id,
	keybinding: 'del',
	context: NavigatorKeybindingContexts.navigatorActive
	});
	if (isOSX) {
	registry.registerKeybinding({
	command: WorkspaceCommands.FILE_DELETE.id,
	keybinding: 'cmd+backspace',
	context: NavigatorKeybindingContexts.navigatorActive
	});
	}