Implement voting functionality

[nagxsan]

Close #1

Summary

• Adds logic for vote_project, withdraw_vote, has_voted and get_vote functions in src/logic/voting.rs
• Update src/tests/voting.rs to include tests for updated code
• Update src/lib.rs to include tests module.

[0xdevcollins]

LGM 🚀

[0xdevcollins]

Hello @nagxsan can you fix this.... your code builds but fails to deploy to testnet