Refactored internal ConnectedReactPortal component

[fkloes]

Description

This pull request refactors the internally used ConnectedReactPortal component to use createPortal from react-dom instead of the react-portal module to render portals that are e.g. used to display dialogs or sheets.

Type of change

• Bug Fix 🐛 (non-breaking change which fixes an issue)
• Enhancement 🚀 (non-breaking change which adds functionality)
• Breaking Change 💥 (fix or feature that would cause existing functionality to not work as expected)
• Polish 💅 (Just some cleanups)
• Internal 🏠 Only relates to internal processes.