1) get generic tests into shape

2) fix instantiation when refrences contain spaces and/or other special characters.
   link to discussion: d5d4f7c8 (comment 196869)

3) fix schemas:
   * ru: mac_addr becomes common CPRI property instead of being Lopcomm-specific
   * ue/cell/nr: ssb_nr_arfcn is fixed to be optional, similarly to cell/nr