Add password complexity checkbox in application settings pages

What does this MR do and why?

!86852 (merged) has been reverted due to jest failure in foss only, see #365492 (closed).

This MR contains the original feature, and move the signup form component test into ee/spec/frontend/admin/signup_restrictions/components/signup_form_spec.js to fix the failed job, because the password complexity checkboxes shoud not be rendered in CE.

Screenshots or screen recordings

see !86852 (merged)

How to set up and validate locally

see !86852 (merged)

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• I have evaluated the MR acceptance checklist for this MR.

/cc @daveliu