LP#1773417 Revamp item and call number tranfers

LP#1773417 Revamp item and call number tranfers

This commit attempts to achieve the goals of both simplification and
feature completeness/flexibility.  In brief, limit the number of
marking and transfer options, then have the code decide the right
action to take given the circumstances.

There are now just two "marking" actions, one at the record level,
one at the holdings level.  The holdings level mark will automatically
mark the destination as specifically as possible from the selected row,
which means either to the library or call number (vol) level.

We are also now down to two transfer options: transfer the selected
item, or transfer the selected call number.  Either option will use
as much given context as possible, then fill in any blanks with
reasonable defaults and actions.

As part of the change, a number of functions and variables are also
renamed.  This is all done for clarification, and in most cases is
due to the variable or function now being used more generally (i.e.
it is used in both the item and vol context, so it is confusing to
be named 'volume_transfer_target', etc.).

Finally, clear up a fair bit of now redundant and unused code.

Signed-off-by: Dan Wells <dbw2@calvin.edu>
Signed-off-by: Mike Rylander <mrylander@gmail.com>