equivalence: compare BMS map OCCURS fields by occurrence -- CBSA BNK1CCA's BNK1ACC (ACCOUNTD OCCURS 10) cannot be cased once #4780 refuses OCCURS maps #4807

Found writing the CBSA equivalence cases (#4270). CBSA BNK1CCA, the customer's accounts screen, translates whole. Its symbolic map BNK1ACC, generated from src/base/bms_src/BNK1ACC.bms, has ACCOUNTD OCCURS 10 TIMES: one 79-byte line per account.

The screen compare reads a map field once, at its first occurrence. #4780 makes screen_layout refuse a map with OCCURS (Unsupported: BMS OCCURS), and test_no_case_map_has_occurs_today fails for the first case whose map has one. So no BNK1CCA case can be proven: GET-CUST-DATA fills up to ten ACCOUNTO(n) lines from INQACCCU's ACCOUNT-DETAILS, and only line 1 would be judged.

Needed. Screen compare by occurrence, as #4765 did for COMMAREAs: each ACCOUNTO(n) compared by name and subscript on both sides (the COBOL side from the SEND MAP bytes, the Java side from the screen view model's occurrences), together with its attribute / colour / highlight subfields. Then lift the refusal for maps that are compared whole.

Then. Add the cbsa-bnk1cca case: first entry, PA / PF3 / PF12 / CLEAR / other key, ENTER with customer 1 (three accounts), with a customer that has no accounts, with a customer not on file, and with a customer number that is not numeric. Chain INQACCCU, INQCUST and ABNDPROC, with cbsa-inqacccu's seed and customer.txt. The generator is in the #4270 CBSA cases handoff.

Part of #4270.