Removes the SAML component from GroupSAML

The SAML IDP will be created at runtime for the Group SAML tests. This is done so that we are not limited to use a single group at runtime. Creating the SAML IDP at runtime will allow us to pass a group name at runtime enabling us split the Group SAML tests into multiple files thus making them simpler and reducing interdependency.

Also moves accept_insecure_certs env variable setting to GitLab component

For this to merge, we will need to skip the group saml sso specs first as the existing tests will break with this change due to removal of the SAML component.