Set identifier on the root folder of imported Globus dataset. Fixes #261

[Xarthisius]

How to test?

1. Import Globus dataset (e.g. doi:10.18126/M2301J)
2. Using Girder UI, navigate to /collection/WholeTale Catalog/WholeTale Catalog/Twin-mediated Crystal Growth: an Enigma Resolved and confirm that meta.identifier is present and equal to doi:10.18126/M2301J

Note: Depends on #263

[codecov]

Codecov Report

Merging #265 into master will not change coverage.
The diff coverage is 0%.

@@           Coverage Diff           @@
##           master     #265   +/-   ##
=======================================
  Coverage   85.55%   85.55%           
=======================================
  Files          38       38           
  Lines        2181     2181           
=======================================
  Hits         1866     1866           
  Misses        315      315

Impacted Files	Coverage Δ
server/lib/globus/globus_provider.py	30.84% <0%> (ø)	⬆️

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