MAE-684: Improvements to membership types validation for payment plans

[olayiwola-compucorp]

Overview

In this PR,

• The validation that prevents users from creating rolling membership with multiple months or years duration is removed.
• Users are prevented from creating a payment plan membership with a lifetime duration
• Prevent users from creating memberships with different duration intervals. i.e. membership_type.period_type, membership_type.duration_units and membership_type.duration_interval must be the same.

Before

After

Users are prevented from creating payment plan membership with life time duration