Pull Request for Issue #14004 .

Summary of Changes

This PR adds the object to the FieldsHelper::extract method as an optional argument. This way extensions can determine in their helper if the context is the proper one for the current object.
It adds a check to the com_contact helper so it can give the correct context (mail or contact) back based on the passed object (item or form).

Testing Instructions

• Assign some custom fields to a contact as well as its mail form and add some values.
• Check the contact in frontend, the fields should show up as expected and form needs to additional fields.

Expected result

Fields show up as expected both in contact and form.

Actual result

Only the added fields for the contact form show up.

Documentation Changes Required

None

Comment

We need this because in com_contact (and maybe 3rd party extensions) the context doesn't differentiate between the contact itself and the contact form. It's always "com_contact.contact". So we need a way to differentiate that, which we can do by looking at the object.
With 4.0, we can change the context for the contact form to "com_contact.mail". The question is if we then should remove the optional argument again (and deprecate it right away now) or if we want to leave it for 4.x. Imho, it wouldn't really hurt to pass it and it may be helpful for 3rd parties.