grafana security, bug fix, and enhancement update

[7.3.6-2]

• change working dir to in grafana-cli wrapper (fixes Red Hat BZ #1916083)
• add pcp-redis-datasource to allow_loading_unsigned_plugins config option
  [7.3.6-1]
• update to 7.3.6 tagged upstream community sources, see CHANGELOG
• remove dependency on SAML (not supported in the open source version of Grafana)
  [7.3.4-1]
• update to 7.3.4 tagged upstream community sources, see CHANGELOG
• bundle golang dependencies
• optionally bundle node.js dependencies and build and test frontend as part of the specfile
• merge all datasources into main grafana package
• change default provisioning path to /etc/grafana/provisioning
• resolve https://bugzilla.redhat.com/show_bug.cgi?id=1843170