Remove mock data to support DAST Site Profile Updation

Proposal

DAST Site Profile displays mock data for Authentication & some additional fields (excluded urls & request headers). They should be removed when backend is ready.

Implementation Plan

HAML

• Remove auth related mock data from ee/app/views/projects/security/dast_site_profiles/edit.html.haml
• Replace them with methods to retrieve DAST site profile field values
• Update specs in ee/spec/views/projects/security/dast_site_profiles/edit.html.haml_spec.rb

Vue

• Remove @client directive from GraphQL queries
• Remove related resolvers
• Update specs if necessary

cc @philipcunningham for awareness