Fixes an infinite loop introduced by #12371
An infinite loop was triggered when there was an error when fetching the
client config.
Cause of the bug: `isLoadedOnce` wasn't set to true when catching an
error in `useClientConfig`.
This effect then created an infinite loop inside
`ClientConfigProviderEffect` because `fetchClientConfig` updated
`clientConfigApiStatus.isLoading` but not `isLoadedOnce`.
```typescript
useEffect(() => {
if (
!clientConfigApiStatus.isLoadedOnce &&
!clientConfigApiStatus.isLoading
) {
fetchClientConfig();
}
}, [
clientConfigApiStatus.isLoadedOnce,
clientConfigApiStatus.isLoading,
fetchClientConfig,
]);
```
Changes for performance improvement.
The primary improvements include replacing GraphQL queries with
REST-based client configuration fetching and making the client config
non render-blocking
