Sorts the list of FLUXNET csv files returned from glob.

[DanielAdriaansen]

Closes #2834.

In the metplus.log file, I see for each season (DJF, MAM, JJA, SON), the list of FLUXNET sites is now always alphabetical:

Starting Terrestrial Coupling Index Calculation for: DJF
FOUND FLUXNET FILES FOR STATIONS:
['AR-SLu', 'AT-Neu', 'AU-ASM', 'AU-Ade', 'AU-Cpr', 'AU-Cum', 'AU-DaP', 'AU-DaS', 'AU-Dry', 'AU-Emr', 'AU-Fog', 'AU-GWW', 'AU-Gin', 'AU-How', 'AU-Lox', 'AU-RDF', 'AU-Rig', 'AU-Rob', 'AU-Stp', 'AU-TTE', 'AU-Tum', 'AU-Wac', 'AU-Whr', 'AU-Wom', 'AU-Ync', 'BE-Lon', 'BE-Vie', 'BR-Sa3', 'CA-Gro', 'CA-NS1', 'CA-NS2', 'CA-NS3', 'CA-NS4', 'CA-NS5', 'CA-NS6', 'CA-NS7', 'CA-Oas', 'CA-Obs', 'CA-Qfo', 'CA-SF1', 'CA-SF2', 'CA-SF3', 'CA-TP1', 'CA-TP2', 'CA-TP3', 'CA-TP4', 'CA-TPD', 'CH-Cha', 'CH-Dav', 'CH-Fru', 'CH-Lae', 'CH-Oe1', 'CH-Oe2', 'CN-Cha', 'CN-Cng', 'CN-Dan', 'CN-Din', 'CN-Du2', 'CN-Du3', 'CN-Ha2', 'CN-HaM', 'CN-Qia', 'CN-Sw2', 'CZ-BK1', 'CZ-BK2', 'DE-Geb', 'DE-Gri', 'DE-Hai', 'DE-Kli', 'DE-Lkb', 'DE-Lnf', 'DE-Obe', 'DE-Seh', 'DE-Tha', 'DK-Eng', 'DK-Fou', 'DK-Sor', 'ES-Amo', 'ES-LJu', 'ES-LgS', 'FI-Hyy', 'FI-Jok', 'FI-Sod', 'FR-Gri', 'FR-LBr', 'GF-Guy', 'GH-Ank', 'GL-ZaH', 'IT-BCi', 'IT-CA1', 'IT-CA2', 'IT-CA3', 'IT-Col', 'IT-Cp2', 'IT-Cpz', 'IT-Isp', 'IT-Lav', 'IT-MBo', 'IT-Noe', 'IT-PT1', 'IT-Ren', 'IT-Ro1', 'IT-Ro2', 'IT-SR2', 'IT-SRo', 'IT-Tor', 'JP-MBF', 'JP-SMF', 'MY-PSO', 'NL-Loo', 'PA-SPn', 'PA-SPs', 'RU-Fyo', 'RU-Ha1', 'SD-Dem', 'SJ-Blv', 'SN-Dhr', 'US-AR1', 'US-AR2', 'US-ARM', 'US-ARb', 'US-ARc', 'US-Blo', 'US-CRT', 'US-Cop', 'US-GLE', 'US-Goo', 'US-IB2', 'US-KS1', 'US-KS2', 'US-LWW', 'US-Lin', 'US-MMS', 'US-Me1', 'US-Me2', 'US-Me3', 'US-Me4', 'US-Me5', 'US-Me6', 'US-NR1', 'US-Ne1', 'US-Ne2', 'US-Ne3', 'US-Oho', 'US-PFa', 'US-Prr', 'US-SRC', 'US-SRG', 'US-SRM', 'US-Sta', 'US-Syv', 'US-Ton', 'US-Tw2', 'US-Tw3', 'US-UMB', 'US-UMd', 'US-Var', 'US-WCr', 'US-Whs', 'US-Wkg', 'ZM-Mon']

And, in the MPR file from Point-Stat, the sites are listed alphabetically as well.

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[georgemccabe]

@DanielAdriaansen and I looked at the output and are OK with the changes. I will make the same change for main_v6.0 and update the truth data for both.