various fixes to dynareParallelDelete.m

- did not account for cases when username not set (namely when remote is localhost)
- did not account for cases when remote directory was not set (namely when remote is localhost)
- added unnecessary `filesep` to `pname` when `pname` was empty
- ignore unused output arguments (it is necessary to explicitly ignore them to prevent unwanted output from the `system` call)
- globbing did not work as it was expanded on the calling machine not the remote; pass call to `bash -c` to handle this

(cherry picked from commit 7a02b3bf)