Figure out problem with long Avangate notification delivery period

[ShockwaveNN]

testing-site-onlyoffice/spec/functional/pricing/site_buy_notification_spec.rb

Line 24 in 4f06c8e

expect(@mail.check_email_by_subject({ subject: TestingSiteOnlyoffice::SiteNotificationData::PAYMENT_RECEIVED }, 300, true)).to be_truthy

In each of the 3 tests here we got two check-ins each:

1. Check email for Avangate mail with checkout info
2. Check email for ONLYLOFFICE mail with details of the purchase

And seems on the Avangate side something is not good and this email took more than 5 minutes. Sometimes it's 7 sometimes it's 20

So we need to split this test somehow but we got several troubles

1. On submit_avangate_order_for_notification reCaptcha may be shown if there is a lot of attempts. So we cannot make this in `befor(:each)
2. We cannot split this spec into several ones easily - there will be conflicts with the same email. We may create different email for each one, but I think it's a rather complicated solution
3. We cannot move 21-23 line in some kind of before(:all) - it results that data is not written to TCM as @amochalov85 confirmed in his exprements

So need to carefully figure out that to do