User Promotion on Profile Update v2.5.1

Adds an per-custom field criteria option to match an empty value.

Preforms a user promotion when:

• A user updates their own profile (Routes under /account).
• When admin's edit a user's profile.
• When a user upgrade is being applied/removed

Modifies notification/user promotion criteria with:

• Allows a Custom Field to match an empty rule (ref)

Performance impact

• User promotion is rebuild when they update their profile.