Restrict Content Pro 3.5.45

Security Fix: Harden permission checks when performing membership actions.
Fix: Auto renew checkbox incorrectly appearing for lifetime memberships.
Fix: Display bug on email search dropdown when manually adding memberships/customers.
Fix: User role granted while membership is still pending.

• New: Add clear membership notes explaining where a cancellation originated from (customer action vs admin action vs webhook).
• New: Add get_user_id() method to RCP_Emails class.
• New: Add $membership parameter to "rcp_subscription_details_action_links" action.
• Tweak: Adjust logic in cron job that expires memberships, which will now allow the 2-day grace period to be removed with custom code.
• Fix: rcp_get_term_restrictions() - Can return an array with "access_level" => "None", which breaks restriction functionality.
• Fix: Registration form not able to be submitted after completing CAPTCHA.

Fix: Membership level not loading correctly in registration form when using the `id` attribute.
Fix: 3.0 migration - force old expiration date to all lowercase to prevent errors with unexpected capitalization on "none" value.