Loosen ExtractKeysOfValueType type check on Formik fields

[fantkolja]

There are issues with field "name" type, I mean the type calculated with the ExtractKeysOfValueType utility.
Especially with a nested object form value type, so if the name is like mapStore.className the utility can't determine the type falling back to never...
I see two options:

• Formik is using a simple string type for all names, we could do the same. But it would be a degradation, since ExtractKeysOfValueType works nice in 90% of cases.
• Add a possibility to turn strict type of bypassing a ready type value, e.g. in the exanple if passing the second generic argument (string) it won't check with ExtractKeysOfValueType

<SelectFieldFormik<MapConfigurationFormValues, string>
   options={customClassesOptions}
   label="Class Name"
   name="mapStore.className"
   disabled={Boolean(errorMessage)}
/>

Comment from @allfayn
We can take one of these strategies:

• try use default string type as a prop, then not have FormValues
• use the second parameter as above
• use recursive type for this complex form values