Fix Script sig push only with OP_DATA_X [Bug]

[jsandinoDev]

• [✅] issue #213
• [✅] follows contribution guide
• [✅] code change includes tests

Refactor the implementation of the is_push_only function.

Closes #213
Closes #216

For the #214 && #215 I think that the problem might be in the

[vercel[bot]]

Someone is attempting to deploy a commit to the keep-starknet-strange Team on Vercel.

A member of the Team first needs to authorize it.