Initial features of accounts tab

It's rough right now, but the accounts tab shows a list of users and
info. Right now the only action available is to apply settings (from
template or another user) to a selection of users. More to come.

scss/bs4/bs4.scss

@@ -1,2 +1,15 @@
 @import "../../node_modules/bootstrap4/scss/bootstrap";
+
+.icon-button {
+    color: $text-muted;
+}
+
+.icon-button:hover {
+    color: inherit;
+}
+
+.icon-button:active {
+    color: $text-muted;
+}
+
 @import "../base.scss";