Follow-up from "SCIM specific token for group SSO" - Convert to Vue

Convert the changes made in https://gitlab.com/gitlab-org/gitlab-ee/merge_requests/9619 into VueJS

Implementation plan

1. Create a new mount element in ee/app/views/groups/saml_providers/_scim_token.html.haml
   • Pass scim_token_url as a data attribute
2. Create a new Vue component (scim_token.vue) in ee/app/assets/javascripts/saml_sso/components
   • Inject scimTokenUrl
   • If scimTokenUrl is null render a Generate a SCIM token button
   • When Generate a SCIM token button is clicked make a network request using SCIMTokenService
   • Render token and url using app/assets/javascripts/vue_shared/components/clipboard_button.vue and GlInputGroup
3. Export initScimToken from ee/app/assets/javascripts/saml_sso/index.js
   • Mount scim_token.vue
   • Parse data attributes
   • Provide scimTokenUrl