Ad-hoc conversions follow as_, to_, into_ conventions (C-CONV)

[FintanH]

We want to follow the conventions outlined here.

Cribbing the table:

Prefix	Cost	Ownership
as_	Free	borrowed -> borrowed
to_	Expensive	borrowed -> borrowedborrowed -> owned (non-Copy types)owned -> owned (Copy types)
into_	Variable	owned -> owned (non-Copy types)

This ticket is to survey if any functions are not following this convention, and if so then fix them.