Add sidebar component

[zhiyanzhaijie]

related: #160

A new sidebar component is added with followed changes:

• r#as and merged_attribute in multiple components

1. in primitive/lib.rs, add meged_attribute for component withr#as, handle class/props of component(TODO: event handler)
2. r#as support - collapsible,tooltip, dropdown_menu

• Style optimization

1. better theme display of separator
2. add gap in dropdown menu item

• Add sidebar component

1. SidebarProvider and others
2. use_sidebar hook
3. use_is_mobile hook (considering the right position in a shared module)
4. doc and variant preview (playwright test)

• Block component type and its display

1. A new component type that need to be show in a isolate html, sidebar as example
2. Change preview/src/main.rs, preview/src/mod.rs to allow block component display, by:
   - 2.1 extend example! macro
   - 2.2 add Route and component for block component, implement isolate envrionment by iframe (Only work in web platform now, not Desktop supported)
   - 2.3 refactoring theme sync, add theme.rs by set theme cookies and sychronize theme change across mutilple iframe by BroadcastChannel
   - 2.4 extractor html (--dark/--light) logic from main.css to dx-component-theme.css

lacks:

1. using extra class in demo of sidebar to correctly show dropdown cotent (need floating ui)
2. tooltip is now not working in sidebar collapsible (overflow: hidden) (need a unifying portal solution, those thing will be nice when mounted in the root of )
3. mege_attribute is now experiment, consult needed

Big changes with r#as in others component, sry about that

[github-actions]

Preview available at https://dioxuslabs.github.io/components/pr-preview/pr-177/