Shared components directory (#579)
* Put Dropdown components in new shared folder
* Move icons to shared dir
* add IconCaredDown to shared folder
* Move ModelPipelineTag
* Move ModelPipelineIcon
* Update imports
* Update WidgetHeader import
* Move files from shared/src to widgets/src/lib
* Move components to widgets/src/lib/components
* Update imports
* Component renaming
* Fix paths
* Move ViewUtils to lib/utils
* Update imports
* Dedupe ViewUtils files
* Move widgets specific functions to helpers.ts
* Rename widgets to js
* Update paths
* Update paths
* Update README.md
* Update working directory in js-widgets-tests.yml
* Linting
* Bug fixes
* Update md file
* Fix type error in Dropdown
