Support multiple errors per transaction

[tombruijn]

I came up with an idea to fake support for multiple errors in one transaction. See this internal private discussion. It's a way to work around the limitations of the transaction API protocol and our current UI, which can only show one error. I would want to work around this by reporting each error as a duplicate transaction of the transaction they were set on (but with different errors).

We will discuss whether we want to support this method with an add_error-type helper to report multiple errors because making this the default behavior will increase plan usage.

[tombruijn]

This has been merged and will be added as the default behavior for Ruby gem 4.0. We're still working on some behavior changes, but in general this is done.