Add more and unify tests for absent object cases

- Unify test data for nonexistence of an object/string and collection.
- Introduce more test through adding missing test data to existing tests.
- Improve logic for checking absence of values to match tests.
- Add missing tests for absent value validation.
- Update documentation to include shared test functionality.

tests/unit/domain/ProjectInformation.spec.ts

@@ -124,7 +124,7 @@ describe('ProjectInformation', () => {
       // assert
       new EnumRangeTestRunner(act)
         .testOutOfRangeThrows()
-        .testUndefinedValueThrows()
+        .testAbsentValueThrows()
         .testInvalidValueThrows(OperatingSystem.KaiOS, `Unsupported os: ${OperatingSystem[OperatingSystem.KaiOS]}`);
     });
   });