Fix context menu blocking keyboard input after closing node graph#3571

Ayush2k02 wants to merge 5 commits intoGraphiteEditor:masterGraphiteEditor/Graphite:masterfrom

Ayush2k02:fix/close-context-menu-on-graph-overlay-closeAyush2k02/Graphite:fix/close-context-menu-on-graph-overlay-closeCopy head branch name to clipboard