Support React 19

[lindelleric]

React 19 support

This PR removes the use of forwardRef, since it's no longer needed in react 19. Ref is now only considered a prop like any other.

Also in this pr is the removal of the deprecated decorators.

Default props are also deprecated by react now.

Left to do

• ~Tests are failing in strange ways. I'm suspecting that we need to upgrade the testing tools.~
• Wait for react team to release 19 stable.
• See comment regarding displayname.
• I switched to yarn as a last resort to get the tests to work, but it should be possible with npm as well.
• ...?