Trials for UBP_v2

Apply UBP trials available only for UBP ab users. It has a similar modal window but with different plans.

It also create some temporary the current user's subscription info for ubp-users in redis(app/models/user.rb:964)

Fallback::Redis.set("user_subscription_#{self.id}", {
    owner_id: self.id,
    counting_date: self.created_at,
    level: self.promo_type,
    billing_cycle: 'monthly',
    }.to_json, number_of_days.days)     

It has number_of_days.days expired period it will destoy by itself after a while. For ubp logic it means when trial-subscription expired after some period powr-counter gets a new(real) info about current subsciption from powr and fills out a new one.

Note. There isn't any worker that is checking the trials period.