Implement insertOrIgnore

[nmalcolm]

Summary of problem or feature request

Oracle doesn't support a syntax such as INSERT IGNORE but since 11g there's a ignore_row_on_dupkey_index hint. I've tried to implement it myself but the comment seems to get stripped. There's also MERGE which might be useful here.

https://stackoverflow.com/questions/9332360/oracle-equivalent-to-mysql-insert-ignore

[yajra]

Laravel docs ref: https://laravel.com/docs/10.x/queries#insert-statements

Will try to implement this feature when I got the chance. Please do not hesitate to submit a PR if you can. Thanks!