add capability to directly add SPs

.../java/edu/kit/scc/webreg/entity/SamlSpMetadataEntity.java

...main/java/edu/kit/scc/webreg/service/saml/SamlHelper.java

...ava/edu/kit/scc/webreg/bean/admin/saml/AddSamlSpBean.java

...va/edu/kit/scc/webreg/bean/admin/saml/EditSamlSpBean.java

.../scc/webreg/bean/admin/saml/ListIdpConfigurationBean.java

...n/java/edu/kit/scc/webreg/bean/admin/saml/ShowSpBean.java

bwreg-webapp/src/main/webapp/admin/saml/add-sp.xhtml

bwreg-webapp/src/main/webapp/admin/saml/edit-sp.xhtml

...-webapp/src/main/webapp/admin/saml/list-idp-configs.xhtml

bwreg-webapp/src/main/webapp/admin/saml/show-idp.xhtml

bwreg-webapp/src/main/webapp/admin/saml/show-sp.xhtml