ProjectRepairer: Refactor to select actions through an enum

repair() takes a 'copyPacks' boolean, which can only describe the one
thing it knows how to do. A second kind of repair would mean a second
boolean at every call site, with the order the two run in implicit in
how repair() tests them.

Take a collection of Action values instead. Individual flags are kept in
flag order. '--full' and the no-flag default use Action.all() so actions
run in enum declaration order. Action has only COPY_PACKS, so behaviour
is unchanged.

Change-Id: Ie7c0d9af40cab893a01a754bc984b8593ff6a5bc