Allow non-BHB identifiers in batch upload

[hmchesner]

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Allow non-BHB identifiers in batch upload
Require additional column for Standard ID Type for literary work, and allow for additional identifiers:

Validation: exact text, per parenthesis below.

Bibliography of the Hebrew Book (BHB)
Incunabula Short Title Catalog (ISTC)
Universal Short Title Catalog (USTC)
Thesaurus of the Hebrew Book (Vinograd)
NLI Yiddish Monographs Union List (ULI)

(All are listed as identifiers here: http://footprints.ccnmtl.columbia.edu/admin/main/standardizedidentificationtype/)