Creates a gt2 transaction used to execute the transaction call
request's
TransactionRequest#getExtendedProperties() are set
as
org.geotools.data.Transaction#putProperty(Object,Object)so that they're available to the lower level API.
These properties can be provided for example by
TransactionPlugin#beforeTransaction(TransactionType) implementations. A typical example is a
custom authentication module providing extra user information that upon transaction commit
can be used by versioning geotools datastore to complete the information required for its
records (such as committer full name, email, etc)