added nf90 interface to read and write 1d string

[weiyuan-jiang]

Description

added nf90 interface to read and write 1d string

Related Issue

Motivation and Context

How Has This Been Tested?

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Trivial change (affects only documentation or cleanup)

Checklist:

• I have tested this change with a run of GEOSgcm (if non-trivial)
• I have added one of the required labels (0 diff, 0 diff trivial, 0 diff structural, non 0-diff)
• I have updated the CHANGELOG.md accordingly following the style of Keep a Changelog

[metdyn]

Thank you, very much, @weiyuan-jiang for your work!
We got the station names printed out nicely!

        string station_name(station_index) ;
                station_name:long_name = "station name" ;

station_name = "Ames_AERO", "Appalachian_State_AERO", "ARM_Oliktok_AK_AERO",
    "ARM_SGP_AERO", "Bakersfield_AERO", "Barrow_AERO", "Billerica_AERO",
    "Bonanza_Creek_AERO", "BONDVILLE_AERO", "Bozeman_AERO",
    "Brookhaven_AERO", "CalTech_AERO", "Cape_San_Juan_AERO", "CARTEL_AERO",
    "Chapais_AERO", "Churchill_AERO", "Cold_Lake_AERO", "Dayton_AERO",
    "Denver_LaCasa_AERO", "DigitalGlobe_Cal_AERO", "EastMalling_MO_AERO",
    "Easton-MDE_AERO", "Egbert_AERO", "EPA-Res_Triangle_Pk_AERO",
    "Fort_McMurray_AERO", "Fresno_2_AERO", "Georgia_Tech_AERO",
    "Goldstone_AERO", "Grand_Forks_AERO", "Granite_Island_AERO", "TROPOZ",
    "Halifax_AERO", "Hart_Miller_Island_AERO", "IMPROVE-MammothCave_AERO",
    "Kangerlussuaq_AERO", "Kellogg_LTER_AERO", "Kelowna_UAS_AERO",
    "Key_Biscayne_AERO", "Kluane_Lake_AERO", "La_Parguera_AERO",