Create test asset overlay

This is a Work-in-Progress, merged current master and some non-trivial merging issues and stylistic touch-ups need to be applied.

src/app/App.jsx

@@ -22,7 +22,7 @@ function App(props) {
       <TestVectorModal
         openModal={openModal}
         testVectors={testAssets.testVectors}
-        activePlayerColumnKeys={testAssets.activeColumnKeys}
+        activeTableColumnKeys={testAssets.activeColumnKeys}
       />
       <AppContainer fluid="xl">
         <Header />