ISSUE-196 implement first attribute builder and simple transcoder

...t/scc/webreg/entity/attribute/AttributeReleaseEntity.java

...du/kit/scc/webreg/entity/attribute/value/ValueEntity.java

...it/scc/webreg/service/oidc/OidcOpScopeLoginProcessor.java

...-webapp/src/main/webapp/user/show-attribute-release.xhtml

...webapp/src/main/webapp/user/show-attribute-releases.xhtml

...ebreg/service/attribute/proc/IdentityValuesProcessor.java

...cc/webreg/service/attribute/release/AttributeBuilder.java

...eg/service/attribute/release/AttributeReleaseHandler.java

regapp-saml-idp/pom.xml

.../edu/kit/scc/webreg/saml/idp/AbstractValueTranscoder.java

...du/kit/scc/webreg/saml/idp/AttributeAuthorityService.java

.../edu/kit/scc/webreg/saml/idp/SamlAttributeTranscoder.java

.../kit/scc/webreg/saml/idp/SingleStringValueTranscoder.java

...ain/java/edu/kit/scc/webreg/saml/idp/ValueTranscoder.java

regapp-saml-sp/pom.xml

...a/edu/kit/scc/webreg/service/impl/AttributeMapHelper.java