Accessibility: Mark required fields as required in xProfile admin

[mercime]

Add (required) to the Name label of:
Add New > Profile Fields
Add New > Profile Field Group

While we have great error messages in case users forget to add the names of the field of field group, let's ensure that new users know that they are required to fill up those fields to prevent any error in the first place.

The alternatives of adding attributes for the input fields like aria-required="true" and required (for HTML5-ready documents) instead only benefit screen reader users. Adding the (required) text in the label would benefit everyone.

[mercime]

In 11169:

Accessibility: Mark xProfile input fields in wp-admin as required.

Error prevention by indicating that the input fields for the Add New Field Name and
Add New Profile Field Group Name are need to be filled up by user.

Fixes #7274.

[mercime]

Excuse my English