change vol2bird text output from fixed delimited to csv

[adokter]

frictionless data packages do not support fixed delimited text, so need to change to csv

[adokter]

• [ ] identify the output file extension and write in csv format whenever the extension is one of txt, tab, csv
• [ ] write metadata to the header in YAML format
• [ ] decide whether to comment out the YAML header with dashes, or use https://csvy.org/
• [ ] decide which metadata to include: likely only user-defineable quantities from options.conf

[adokter]

vp-parser for R being developed here: https://github.com/enram/vp-parser

[peterdesmet]

FYI, these are the metadata properties we discussed being relevant:

RADAR
/where/lon              5.176           [Double]    #Longitude
/where/lat              52.101          [Double]    #Latitude
/where/height               44.0            [Double]    #Height of the radar antenna [m] a.s.l.
/how/beamwidth              1.0         [Double]    #radar beam width [deg]
/how/wavelength             5.3         [Double]    #radar wavelength [cm]

FILE
/what/date              "YYYYMMDD"      [String]    #Nominal Date (copy from volume file) -> link to data
/what/time              "HHmmss"        [String]    #Nominal Time (copy from volume file) -> link to data
/what/source                "WMO:xxxxx"     [String]    #Radar (copy from volume file)

SETTINGS
/how/clutterMap             "clutter.h5"        [String]    #Filename of cluttermap [string]
/how/dealiased              0           [Long]      #Whether dealiased radial velocities were used [0 no, 1 yes]
/how/enddate                "YYYYMMDD"      [String]    #Date (nominal date from last scan)
/how/endtime                "HHmmss"        [String]    #Time (nominal time from last scan)
/how/sd_vvp_thresh          2.0         [Double]    #VVP radial velocity standard deviation [m/s]
/how/minrange               5.0         [Double]    #Minimum range [km] used for profile
/how/maxrange               25.0            [Double]    #Maximum range [km] used for profile
/how/minazim                0.0         [Double]    #Minimum azimuth used for profile
/how/maxazim                360.0           [Double]    #Maximum azimuth used for profile
/how/rcs_bird               10.0            [Double]    #Assumed bird radar cross-section [cm2]
/how/task               "vol2bird"      [String]    #Name of the program that generated this file
/how/startdate              "YYYYMMDD"      [String]    #Date (nominal date from first scan)
/how/starttime              "HHmmss"        [String]    #Time (nominal time from first scan)
/how/task_args              "{see below}"       [String]    #Arguments of the program that generated this file
/how/task_version           0.2.2           [String]    #version of the program that generated this file
/how/comment                "Birds only"        [String]    #Indicator of how these profiles were generated