JBoss Transactions SPI is missing TwoPhaseOutcome constants

The jboss-transaction-spi allows applications to be decoupled from Narayana's implementation details, however the ImportedTransaction#doPrepare method returns an integer that is defined by constants in a class inside of com.arjuna.ats.arjuna.coordinator. These constants should be copied into the SPI.

The workaround is to copy the constant values.