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/Sidebar/SidebarTrigger.scss

@@ -0,0 +1,34 @@
+@import "../../css/variables.module";
+
+.excalidraw {
+  .sidebar-trigger {
+    @include outlineButtonStyles;
+
+    background-color: var(--island-bg-color);
+
+    width: auto;
+    height: var(--lg-button-size);
+
+    display: flex;
+    align-items: center;
+    gap: 0.5rem;
+
+    line-height: 0;
+
+    font-size: 0.75rem;
+    letter-spacing: 0.4px;
+
+    svg {
+      width: var(--lg-icon-size);
+      height: var(--lg-icon-size);
+    }
+  }
+
+  .default-sidebar-trigger .sidebar-trigger__label {
+    display: none;
+
+    @media screen and (min-width: 1024px) {
+      display: block;
+    }
+  }
+}