Fix: React 18 markers

[BenHodgsonR2R]

Issue: (#1223)

This pull request addresses an issue with the markers rendering incorrectly using React ^18.

The issues were:

1. StrictMode behaves differently, which exposes an issue with the dimensionsCache property in componentWillUnmount.
   https://react.dev/blog/2022/03/29/react-v18#new-strict-mode-behaviors
2. Batched updates, causing flickering with the markers when the map is repositioned or zoomed. Resolved by opting out of automatic batching for the marker state updates (via flushSync).
   https://react.dev/blog/2022/03/29/react-v18#new-feature-automatic-batching

[AaronLayton]

+1 👍 for this

[managervcf]

@itsmichaeldiego This really needs to be merged. Otherwise, this library will naturally die.

[rubberbandage]

+1 for this to be merged

[Mbes9]

+1 to merge this...

[RobotScribe]

+1

[maanenh]

+1