DRILL-7181: Improve V3 text reader (row set) error messages Adds an error context to the User Error mechanism. The context allows informatio…
DRILL-7181: Improve V3 text reader (row set) error messagesAdds an error context to the User Error mechanism. The context allowsinformation to be passed through an intermediate layer and applied whenerrors are raised in lower-level code; without the need for thatlow-level code to know the details of the error context information.Modifies the scan framework and V3 text plugin to use the framework toimprove error messages.Refines how the `columns` column can be used with the text reader. Ifheaders are used, then `columns` is just another column. An error israised, however, if `columns[x]` is used when headers are enabled.Added another builder abstraction where a constructor argument listbecame too long.Added the drill file system and split to the file schema negotiatorto simplify reader construction.Added additional unit tests to fully define the `columns` columnbehavior.