Enhancement: Change asterisk placement

[ipokkel]

Is your feature request related to a problem? Please describe.
By default, the asterisk for a required field is placed after an input element resulting in each selector in a radio input group having an asterisk placed next to it.

Describe the solution you'd like
If the showmainlabel option is not set to false, we could consider placing the asterisk for required fields inside the label.

Describe alternatives you've considered
Change the location of the .pmpro_asterisk span with JavaScript.

Additional context
Moderators Only - Support Ticket