Display a "Name on card" input on payment step

It creates a name column on spree_credit_cards table to insert the data
instead of using the old first_name and last_name fields, fixes #2486
Move payment partial from core to frontend

Plus make it use the name attribute instead of the deprecated first_name
and last_name
Add CHANGELOGs entries for payment name on card feature
Merge branch 'master' into refactor-calculators