FR: make C-c C-c for storing remember notes optional

[Adam Spiers <orgmode@adamspiers.org>]

Simple feature request:

Could we make it optional whether C-c C-c is required to store a note,
on a per-template basis?  This makes most sense when it is known in
advance that the only things which might need to be changed within the
template are already taken care of via %^{foo} prompts.  So when all
the prompts have been entered, the final <enter> keystroke will store
the note immediately, rather than the user having to type <enter> C-c
C-c.