Revert "libsepol: filename_trans: use some better sorting to compare and merge"

This change was incorrect and can yield duplicate file name transition rules.
Revert it and look at converting the filename_trans list to a hashtab
as has already been done in the kernel in the future.

This reverts commit a29f6820c52b60b9028298cde9962dd140bbf9ea.

Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>
Improve error message for name-based transition conflicts.

Quote the component name.
Reorder the arguments to more closely align with the rule syntax.
Use a more descriptive text that will more clearly correspond to the original rule.

Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>