Authorization header to X-DS-Authorization in backend_srv.js

fix(templating): fixed issue with detecting data source variable in other template variable definition, fixes #5165

closes #5167

fix(templating): fixed issue with nested template variables and multi select, the child variable selection state is now updated like single select variables, so if none matches the first option is selected, fixes #4861

Conflicts:
	package.json

Commit adds missing option `Read-Only Editor` to `auto_assign_org_role` description.

Conflicts:
	pkg/api/frontendsettings.go