Message usage actual sent, suppressed or custom gateway should be counted separately

# Problem

Incorrect usage quota consumption when test mode is on

When test mode is on, and a SMS is sent to a phone number that should not receive SMS, and the should be counted separated and should not be billed.

Can this be used for billing?

No files, tests, or entry points are named. Start by locating the message-usage and quota/billing accounting paths, then clarify how actual sends, suppressed messages, and custom-gateway messages should be counted; done means these categories are separate and suppressed test-mode messages are not billed.

Written by the indexing model from the issue text.