Read-Only transaction key for Transaction Details API

[sjones123]

Idea: A read-only key that can be generated specifically for the Transaction Details API.

Background:

We are developing an app that only uses the Transaction Details API.

Which means we are only reading information.

From a liability standpoint, we want to avoid saving a write-capable transaction key.

Ideally a separate "read-only" transaction key could be created when a user turns on the Transaction Details API.