feat: add NgBvnRecognizer (Nigerian BVN) and KeNationalIdRecognizer (Kenyan national ID)

[kingztech2019]

Change Description

Adds two new country-specific PII recognizers for African identifiers currently absent from Presidio:

NgBvnRecognizer — Nigerian Bank Verification Number (NG_BVN)

The BVN is an 11-digit identifier issued by the Central Bank of Nigeria (CBN) and managed by NIBSS (Nigerian Interbank Settlement System). It links every bank account held by an individual to a single biometric record. Unauthorized disclosure is a criminal offence under the CBN BVN Regulatory Framework (Circular FPR/DIR/GEN/CIR/01/009, 2014).

Design notes:

• Pattern \b\d{11}\b at score 0.01 — same footprint as the existing NgNinRecognizer
• BVN has no publicly documented checksum algorithm. validate_result returns None (not True) for structurally valid matches so context-boosted score is preserved rather than unconditionally promoting to MAX_SCORE
• Context: bvn, bank verification number, bank verification no, nibss, bank identity number

KeNationalIdRecognizer — Kenyan National Identity Card (KE_NATIONAL_ID)

The Kenyan national ID card number is a 7–8-digit sequential identifier issued by the National Registration Bureau under the Registration of Persons Act (Cap. 107). Kenya currently has no recognizers in Presidio — this is the first.

Design notes:

• Pattern \b\d{7,8}\b at score 0.01 — covers 7-digit (older cards) and 8-digit (current cards)
• No checksum algorithm is publicly documented; validate_result returns None for structurally valid matches
• Context: national id, national identity, nid, kenyan id, kenya national id, id card, national registration

Both recognizers are registered in default_recognizers.yaml with enabled: false.

Issue reference

N/A — new recognizer addition for uncovered African PII entities.

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