Support REFERENCES ON construction

[kliushnichenko]

Adding ON DELETE CASCADE or similar ON construction after REFERENCES ... leads to an empty parse result.
It would be nice to support ON also.

Thanks! Cool parser BTW :)

[xnuinside]

@walkman90 , hello & thank you! Good addition. I will be back from vacation on 31 March and will add support in parser.

[xnuinside]

@walkman90 hello! I added feature in release 0.9.0 (already released). Example of output: https://github.com/xnuinside/simple-ddl-parser/blob/main/tests/test_references.py#L37. Please comment if you will find any issues or need to add smth else.

[xnuinside]

I will close issue as done, if you will have anything more - feel free to open a new one.