Add in feature to allow auto-printing of package label when "Put in
Pack" button is pushed. Note there are 2 choices for package labels and
these choices are hardcoded in as selection options to avoid complexity
of finding all relevant reports (i.e. custom report labels won't be
auto-printable) and exclude the irrelevant reports.
Unfortunately since there are different flows for "Put in Pack", a
separate "_post_put_in_pack_hook" method is needed to manually be called
in some of these cases and additional future use cases will also require
it to be called if this feature is desired in that case.
Additionally clean up _put_in_pack() since it was only called by methods
with ensure_one(), but was semi-designed to handle multiple pickings
(but only returned 1 package in the end, which didn't make sense + had
other errors in it).
Part of task: 3046178 - At package creation (put in pack)
Part-of: odoo/odoo#126791
Tiffany Chang (tic)
a736d3278b