fix: add delete button for groupings

Ui/Tabs/DatabaseTab.cs

@@ -44,15 +44,27 @@ internal class DatabaseTab : ITab {
         }
 
         var first = true;
+        GroupBy? remove = null;
         foreach (var groupBy in this.GroupBys) {
             ImGui.TextUnformatted(
                 first
                     ? $"Group by {Enum.GetName(groupBy)}"
                     : $"then by {Enum.GetName(groupBy)}"
             );
+
+            ImGui.SameLine();
+
+            if (ImGuiComponents.IconButton($"remove-{groupBy}", FontAwesomeIcon.Times)) {
+                remove = groupBy;
+            }
+
             first = false;
         }
 
+        if (remove != null) {
+            this.GroupBys.Remove(remove.Value);
+        }
+
         Vector2 buttonSize;
         ImGui.PushFont(UiBuilder.IconFont);
         using (new OnDispose(ImGui.PopFont)) {