formatter: move most of template option helper to formatter
We want to share this function between formatter and cmdutils. It
doesn't belong in templater because it imports knowledge of ui layers
that shouldn't be there. We'd prefer cmdutil to layer on the formatter
rather than vice-versa. Since the formatter is the handler for -T
options for all non-log commands, let's move the helper there. We
leave the bits specific to the old --style option behind.
(binary:application/octet-stream)