merged BNF and ABNF parsing

[Carlyle-Foster]

this change allowed me to compress the tests for BNF and ABNF syntax parsing.

this time the diff should be much clearer.

[coveralls]

coverage: 97.02% (-0.09%) from 97.109%
when pulling 96bf47c on Carlyle-Foster:main
into a8e52a3 on shnewto:main.

[Carlyle-Foster]

could i add the commit that changes parsers/mod.rs to parsers.rs to this? u could still see the good diff by looking at the changes only from the first commit and u could just not squash them so it ends up the same way as if i sent that PR later