ligolw_run_sqlite: port to dbtables.workingcopy
This fixes issues like:
Traceback (most recent call last):
File "/usr/bin/ligolw_run_sqlite", line 94, in <module>
dbtables.set_temp_store_directory(connection, options.tmp_space, verbose = options.verbose)
AttributeError: module 'ligo.lw.dbtables' has no attribute 'set_temp_store_directory'
I have tried to preserve the logic as much as possible during the port, but due to how the working copy is introduced, it's done in a slightly different order which should end up being equivalent.
I have also modified the conditional logic for checking the file type (xml/sqlite) slightly, to simplify some code paths and remove a path that will never be triggered. Hopefully that's okay.