feat: Add "new doc" button on collections in sidebar (#3174)

* feat: Add new icon button on collections in sidebar, move sort into menu

* Remove unused menu, add warning when dragging in a-z collection

* fix: Add hover background to sidebar actions, add tooltip to new doc button

* Retain 'active' state on buttons when related context menu is open

* fix: Two more spots that deserve active background

app/components/Sidebar/components/SidebarButton.tsx

@@ -71,7 +71,8 @@ const Wrapper = styled(Flex)<{ minHeight: number }>`
   cursor: pointer;
 
   &:active,
-  &:hover {
+  &:hover,
+  &[aria-expanded="true"] {
     color: ${(props) => props.theme.sidebarText};
     transition: background 100ms ease-in-out;
     background: ${(props) => props.theme.sidebarActiveBackground};