feat: sidebar tabs support (#6213)

* feat: Sidebar tabs support [wip]

* tab trigger styling tweaks

* add `:hover` & `:active` states

* replace `@dwelle/tunnel-rat` with `tunnel-rat`

* make stuff more explicit

- remove `Sidebar.Header` fallback (host apps need to render manually), and stop tunneling it (render in place)
- make `docked` state explicit
- stop tunneling `Sidebar.TabTriggers` (render in place)

* redesign sidebar / library as per latest spec

* support no label on `Sidebar.Trigger`

* add Sidebar `props.onStateChange`

* style fixes

* make `appState.isSidebarDocked` into a soft user preference

* px -> rem & refactor

* remove `props.renderSidebar`

* update tests

* remove

* refactor

* rename constants

* tab triggers styling fixes

* factor out library-related logic from generic sidebar trigger

* change `props.onClose` to `onToggle`

* rename `props.value` -> `props.tab`

* add displayNames

* allow HTMLAttributes on applicable compos

* fix example App

* more styling tweaks and fixes

* fix not setting `dockable`

* more style fixes

* fix and align sidebar header button styling

* make DefaultSidebar dockable on if host apps supplies `onDock`

* stop `Sidebar.Trigger` hiding label on mobile

this should be only the default sidebar trigger behavior, and for that we don't need to use `device` hook as we handle in CSS

* fix `dockable` prop of defaultSidebar

* remove extra `typescript` dep

* remove `defaultTab` prop

in favor of explicit `tab` value in `<Sidebar.Trigger/>` and `toggleSidebar()`, to reduce API surface area and solve inconsistency of `appState.openSidebar.tab` not reflecting actual UI value if `defaultTab` was supported (without additional syncing logic which feels like the wrong solution).

* remove `onToggle` in favor of `onStateChange`

reducing API surface area

* fix restore

* comment no longer applies

* reuse `Button` component in sidebar buttons

* fix tests

* split Sidebar sub-components into files

* remove `props.dockable` in favor of `props.onDock` only

* split tests

* fix sidebar showing dock button if no `props.docked` supplied & add more tests

* reorder and group sidebar tests

* clarify

* rename classes & dedupe css

* refactor tests

* update changelog

* update changelog

---------

Co-authored-by: barnabasmolnar <barnabas@excalidraw.com>

src/components/LibraryMenu.scss

@@ -1,9 +1,9 @@
 @import "open-color/open-color";
 
 .excalidraw {
-  .layer-ui__library-sidebar {
-    display: flex;
-    flex-direction: column;
+  .library-menu-items-container {
+    height: 100%;
+    width: 100%;
   }
 
   .layer-ui__library {
@@ -11,28 +11,6 @@
     flex-direction: column;
 
     flex: 1 1 auto;
-
-    .layer-ui__library-header {
-      display: flex;
-      align-items: center;
-      width: 100%;
-      margin: 2px 0 15px 0;
-      .Spinner {
-        margin-right: 1rem;
-      }
-
-      button {
-        // 2px from the left to account for focus border of left-most button
-        margin: 0 2px;
-      }
-    }
-  }
-
-  .layer-ui__sidebar {
-    .library-menu-items-container {
-      height: 100%;
-      width: 100%;
-    }
   }
 
   .library-actions-counter {
@@ -87,10 +65,17 @@
     }
   }
 
-  .library-menu-browse-button {
-    margin: 1rem auto;
+  .library-menu-control-buttons {
+    display: flex;
+    align-items: center;
+    justify-content: center;
+    gap: 0.625rem;
+  }
 
-    padding: 0.875rem 1rem;
+  .library-menu-browse-button {
+    flex: 1;
+
+    height: var(--lg-button-size);
 
     display: flex;
     align-items: center;
@@ -122,30 +107,19 @@
     }
   }
 
-  .library-menu-browse-button--mobile {
-    min-height: 22px;
-    margin-left: auto;
-    a {
-      padding-right: 0;
-    }
+  &.excalidraw--mobile .library-menu-browse-button {
+    height: var(--default-button-size);
   }
 
-  .layer-ui__sidebar__header .dropdown-menu {
-    &.dropdown-menu--mobile {
-      top: 100%;
-    }
+  .layer-ui__library .dropdown-menu {
+    width: auto;
+    top: initial;
+    right: 0;
+    left: initial;
+    bottom: 100%;
+    margin-bottom: 0.625rem;
+
     .dropdown-menu-container {
-      --gap: 0;
-      z-index: 1;
-      position: absolute;
-      top: 100%;
-      left: 0;
-
-      :root[dir="rtl"] & {
-        right: 0;
-        left: auto;
-      }
-
       width: 196px;
       box-shadow: var(--library-dropdown-shadow);
       border-radius: var(--border-radius-lg);