fix(analyzer): normalize case before fi hetu and sg uen checksums

[uwezkhan]

Change Description

validate_result in two recognizers compares a check character against an upper-case reference without normalizing case. Patterns are matched with regex.IGNORECASE, so a valid ID written with a lower-case letter matches the pattern but is then dropped by the checksum, so the entity is not returned.

• FiPersonalIdentityCodeRecognizer compares the HETU control character against "0123456789ABCDEFHJKLMNPRSTUVWXY".
• SgUenRecognizer compares the UEN prefix, entity-type and check letter against upper-case tables (all three formats).

Before: 131052-308t and 53125226d match the regex, fail validation, and are not detected.
After: the check character is upper-cased before the comparison, so both detect at the same span and score as their upper-case forms. Invalid checksums stay rejected, so no new false positives.

Same normalization #2076 applied to the ES NIF/NIE recognizers. Added lower-case regression cases to both recognizer test files.

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