Add offset and length argument to pycurl absorb and squeeze

[mlouielu]

Currently, pycurl absorb and squeeze only have trits argument, but pykerl have offset and length.

Although pycurl is a deprecated hash function, but in IRI snapshot, it used CURLP81 to sign the snapshot, so if we want to verify snapshot signature, we will need offset and length argument to used absorb and squeeze.

[todofixthis]

Hey @mlouielu thanks for reporting this!

Looks fairly straightforward to implement this; I'm going to tag this issue with help wanted.

[todofixthis]

Scheduled for release: 2.0.4

Thanks Louie!!