[IMP] crm,sale,*: Improve UX

This commit improves the ux in CRM by changing a few things:
  - Restore the use_leads and use_quotations fields
    along with their features as they were in 12.0.
  - Hide the email alias if use_upportunities and use_leads
    are unchecked.
  - Show a link to the general settings instead of the alias_domain
    if no alias_domain has been configured.
  - fixes the "unassigned lead(s)" link so that
    it redirects the user to the actually unassigned leads

Task: #1962182
PR: #32372