Fix useFormGroup doesn't return validation errors with react-hook-form 7.53.0

[slax57]

Problem

With the latest version of react-hook-form (7.53.0 at the time of writing), useFormGroup no longer returns validation errors correctly.

This causes issues such as the TabbedForm Tab header not being colored in red when there is a validation error on one of the inputs inside the Tab.

Solution

An issue was opened on RHF repo to let them know about this regression: react-hook-form/react-hook-form#12217

However, it seems this issue also highlights that we may not being using the form state correctly to compute the form group state, hence we figured we may as well improve the useFormGroup hook to be compatible with all versions of RHF.

How To Test

1. Update RHF to its latest version yarn up react-hook-form
2. Run the test TabbedForm.spec.tsx > should set the style of any Tab button with errors on submit and make sure it passes

Additional Checks

• The PR targets master for a bugfix, or next for a feature
• The PR includes unit tests (if not possible, describe why) -> we can rely on existing unit tests
• The PR includes one or several stories (if not possible, describe why) -> not necessary
• The documentation is up to date -> no change necessary

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