selectField() and selectFieldValues() are trivial, they just need to
pass it through to select(). In fact, selectFieldValues() was already
doing it, just no one ever updated IDatabase.
insertSelect() is a little more work. nativeInsertSelect() was
originally written as largely a copy-paste of select() and has since
gotten well out of sync. Now that we have selectSQLText(), we should be
able to just use that. DatabasePostgres's implementation can wrap the
parent implementation instead of being another copy-paste, but
DatabaseOracle seems to still need to be special.
Change-Id: I0e6a9e6daa510639d3212641606047a5db96c500
31cb62dd2d