[G2M] Accordion/PanelBase - add overflow prop, change transition type & add opacity and overflow to open cases

[geoerika]

Changes:

Accordion/PanelBase

• change transitiontype to transition-opacity & move overflow& add opacityto different open cases
• removed autoHeight prop, simplify className for children's div & add overflow prop to allow overflow in needed cases

This solves the following problem in widget-studio where I am trying to use the Accordion with a few Dropdown Selectelements that have list menus that overflow the accordion panels

Before:

https://user-images.githubusercontent.com/41120953/167925732-8eba2b83-b2e9-4743-8ba0-41b96a6e9cb1.mov

After:

https://user-images.githubusercontent.com/41120953/167925359-30e8f7c2-a0aa-4c51-8f12-c9a844b6c021.mov

[github-actions[bot]]

📚 Storybook preview (updated to fd642263004a5727232152d3633a5eac4b3d5c14)

[geoerika]

looks good! Maybe give an example in the stories on the usage of overflow

Sorry for the delay on this. Will finish next week!