Adapt the setup and defaults of the nds process

Changes:

• change the name of the socket from pipe to daqd_socket to better reflect its purpose
• change the arg parsing to use the args library
• change the nds process to take a path to the socketdir (or working directory) which houses the daqd_socket and the jobs directory
• change the nds process to attempt to create the jobs dir if needed
• default the socketdir to /var/run/nds to get a reasonable default
• update the daqd to default to /var/run/nds for the nds_jobs_dir
• update the daqd to use daqd_socket instead of pipe for communication with the nds
• update the ctest test_daqd_nds to use --socketdir for communication

The goal of this is to help regularize the nds process and ease the setup for systemd.