refactor(toolkit): Update folder structure and cleanup assistants_web (#729)
* wip
* create UI folder
* layout folder
* fix
* layout imports
* layout folder fixes
* update organization
* fix
* import all hooks
* common constants import
* utils export
* fixes
* code feedback
* code feedback
---------
Co-authored-by: Khalil Najjar <knajjars@gmail.com>