ui: Keyboard controls (#935)

* switch focus between views with Tab
* move focus within views with WASD/HJKL/Arrows
* move focus between graph edges by holding Shift
* move focus between code references by holding Shift
* removed graph panning with WASD and moved zooming to Alt + W/S
* removed graph navigation by pressing starting character in graph view lists
* changed local reference and custom trail shortcuts
* updated Keyboard Shortcuts window
* use common back and forward shortcuts and YZ & Shift + YZ
* fix macOS issue where widgets don't get proper focus after creating a new tab
* don't use shared_ptr in QtMainView

fixes #486, #327, #214, #210

testing/keyboard_controls/data/history_tests.cpp

@@ -0,0 +1,59 @@
+
+#define HISTORY_TESTS
+
+// TEST: Graph focus restored on back
+// START ----------------------------------------------------------------------
+
+class HistoryTest // <- ACTION: activate
+{
+public:
+	int member;
+	int member2;
+};
+
+int func()
+{
+	HistoryTest h;
+	h.member = 0;
+}
+
+// ACTION: Focus and activate 'func' in graph
+// ACTION: Navigate 'back' in history
+// RESULT: The graph for 'HistoryTest' is restored with focus at 'func'
+
+// END ------------------------------------------------------------------------
+
+
+
+// TEST: Graph aggregation focus restored on back
+// START ----------------------------------------------------------------------
+
+class HistoryTestUser
+{
+public:
+	int process()
+	{
+		h.member = 2;
+		h.member2 = 4;
+	}
+
+	HistoryTest h;
+};
+
+// ACTION: Focus and activate aggregation 'HistoryTestUser -> HistoryTest'
+// ACTION: Navigate 'back' in history
+// RESULT: The graph for 'HistoryTest' is restored with focus at aggregation edge
+
+// END ------------------------------------------------------------------------
+
+
+
+// TEST: Code focus restored on back
+// START ----------------------------------------------------------------------
+
+HistoryTest createTest(); // <- ACTION: focus and activate 'createTest' from code
+
+// ACTION: Navigate 'back' in history
+// RESULT: The code view is restored with focus at 'createTest'
+
+// END ------------------------------------------------------------------------