Refactor + fix for tests.declarative.
Refactor + fix for tests.declarative.

    * Refactor imports in tests for lkbutils.declarative.
    * Supplement lacking asserts for property definitions.

drowse314-dev-ymat/lexical-knowledge-base-for-japanese-civil-law,drowse314-dev-ymat/lexical-knowledge-base-for-japanese-civil-law