Add dropdown component

[mklanjsek]

Describe the problem/challenge you have
Dropdown component has been requested by Octant community and is required for improving the breadcrumbs (#1212). It will help users and especially plugin developers when a single value has to be selected among multiple input values as well as with the navigation.

Describe the solution you'd like
Create a component based on Clarity dropdown:
https://clarity.design/documentation/dropdowns

Expose component interface that's similar to other Octant components.

Anything else you would like to add:
Add storybook story and document exposed properties