API: Query::seek() and Query::rewind() no longer return a value.
Although breaking an API inside a patch release may seem odd, this in
fact is correcting a long-standing bug in our implementation of
Iterator::rewind(), so I think it’s appropriate.
https://github.com/silverstripe/silverstripe-framework/issues/9097
This ensures that numeric fields appear in PHP as int/float values
rather than strings, which allows the development of more type-safe PHP
code.
This doesn’t work on the legacy mysql driver and this will now throw
a notice-level error. It requires mysqlnd.
