Changed return types in ElasticSocialSettings to allow encryption and decryption of secrets

To allow that the secret settings in the Elastic Social Credentials document can be stored as encrypted secrets instead of only plaintext strings, the return types of the respective getters in the com.coremedia.blueprint.base.elastic.social.configuration.ElasticSocialSettings had to be changed to java.lang.Object.

Follow Section, “Changed return types in ElasticSocialSettings to allow encryption and decryption of secrets” for upgrade information.

(CMS-25260)