Add `useFieldMeta()`

[bblanchon]

Is your feature request related to a problem? Please describe.

I created a collection of form components, and I want to style the required fields differently. I can tell which fields are required by looking at meta.required, but meta is currently only available through useField().

Describe the solution you'd like

I suggest adding useFieldMeta() to return the field's meta.

Describe alternatives you've considered

I tried useField(), but it causes issues when the field needs options (such as {type:"checkbox"}) because it alters the field's behavior.

Adding useFieldRequired()/useIsFieldRequired() would also be a suitable solution to my issue, but I noticed that the documentation never mentions meta.required, so I assume this property isn't always available.