[App] SDK integrations

[1Mateus]

• [x] Faucet
• [x] Transaction (Deposit/Withdraw)
• [x] Key Derivation
• [x] Update Serverless to save more events on testnet indexer
• [x] Load and Cache UTXO's
• [ ] Correct loads SDK in server side
• [ ] Correct loads Snarkjs/Circomlibs in server side

[veigajoao]

delta = delta < 0n ? bn128.r + delta : delta;

[veigajoao]

Use babyjub curve in keypair

[1Mateus]

Create utxos_out with the sum of smaller utxos_in