DORIS RINEX

[gwbres]

• This PR submits initial support of DORIS RINEX files
• DORIS RINEX files are special Observation RINEX files that are easier to deal with.
  This only requires a few tweaks in the existing Observation cases
• The ESA DORIS mission is dedicated to high accuracy geoid mapping
• While adding those tweaks I realized the existing code could benefit some improvements.
  Mainly, removing some memory allocation (Collect::<>). This will slightly improve the existing library performances
• Adds or improves DORIS and possibly shared objects, like DOMES the station identification code,
  which is used in DORIS and in several other cases
• I'm not closing the DORIS topic considering:
  • this is just initial support (basically: data identification & parsing)
  • not supported yet in the processing toolbox and command line apps