Records missing 260$c

[HirschSt]

260$c is required if anything in the 260 block is filled out (like a city name). Of the ca. 12,000 errors, ca. 10,000 are from the ICCU import.

@xhero will exclude the ICCU records from this validation (see spreadsheet tab "260 c required"), records that start with 850

This is from the Health Report error "260-c: required."

[xhero]

Added exclusions https://github.com/rism-digital/validation-exclusions/commit/bfcbb002a9033220e7ab1da7cb2c10a72afb06fe

[jenniferward]

Exclusions added and reflected in health report. The remaining 26 will be done by hand.