Add unit tests for BaseHyphenatedIdentifierValidator

[JasonWang-0401]

Description of what I changed

Adds BaseHyphenatedIdentifierValidatorTest, a unit test for the abstract base class
BaseHyphenatedIdentifierValidator that all of the "hyphenated check-digit" patient-identifier
validators (LuhnIdentifierValidator, VerhoeffIdentifierValidator) inherit from. The base
class previously had no direct test — its behaviour was only exercised indirectly through the
two subclass tests, where it is entangled with each subclass's own check-digit algorithm
(LuhnIdentifierValidatorTest even carries a // TODO split this into multiple tests note).

The new test uses a tiny stub subclass with a fixed, caller-controlled check digit so the shared
base-class contract can be verified in isolation, independent of any real check-digit math:

• getValidIdentifier appends - + the correct check letter (the full 0→A … 9→J mapping,
  and X for an out-of-range digit)
• isValid returns true/false correctly, accepts the check letter case-insensitively, and
  works whether the check digit is supplied as a letter (id-D) or an integer (id-3)
• malformed input throws UnallowedIdentifierException (no hyphen, trailing hyphen, multi-character
  check digit, a check character that is neither A–J nor a digit)
• the allowed-character rules reject null / empty / whitespace / disallowed characters

Pure JUnit 5; no Spring context and no database, so it runs in milliseconds. No production code is
changed.

Issue I worked on

Test-coverage improvement for a previously-untested base class. This change is purely additive
test code with no production changes.

see https://issues.openmrs.org/browse/TRUNK-

Checklist: I completed these to help reviewers :)

• My IDE is configured to follow the code style of this project. (Tabs for indentation,
  line length ≤ 125, and import ordering match the surrounding test files.)
• I have added tests to cover my changes.
• I ran mvn clean package right before creating this pull request. (Verified the change with
  ./mvnw -pl api test -Dtest=BaseHyphenatedIdentifierValidatorTest → Tests run: 10, Failures: 0, Errors: 0.)
• All new and existing tests passed.
• My pull request is based on the latest changes of the master branch.

🤖 Generated with Claude Code

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

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