feat(sessions): updating the cosign signing and the bundler

[geekbrother]

Description

This PR is making the following changes to the Co-Signing endpoint:

• Changing the signature to comply with the Ethereum signing flow, using the LocalWallet and packing the signature.
• Changing the bundler function and variables to not be sticked to the Biconomy (BICONOMY_BUNDLER_* -> BUNDLER_*) and changing the default bundler to the Pimlico.
• Changing the request userOperation struct to be v07 from v06 to proper calculation of the packed UserOperation.
• Adding calculation of the additional fields (paymaster, factory) for the packed UserOperation structure builder to support paymasters.
• Multiple fixes and crypto utils functions refactors.

How Has This Been Tested?

This flow was tested manually with the testing dapp cosigning flow.

Due Diligence

• [ ] Breaking change
• [ ] Requires a documentation update
• [ ] Requires a e2e/integration test update

[geekbrother]

We'll need tests here soon!

Totally! I'm testing by the manual run of the integration test now, since we need a gas to make the full flow. I'm thinking to reduce the test to just the validation/simulation step for the CI/CD integration tests.