Broker Integration Testing

[bowd]

Description

⚠️ This branch is based off feature/mcmint-mvp + #9848 Once #9848 is merged in featurue/mcmint-mvp this branch should be updated to reflect any changes, before it can also be merged.

Add integration tests tying all McMint related work together.

Things to test:

• [x] Stable to Collateral swaps
• [x] Stable to Stable swaps
• [ ] Bucket updates
• [ ] Discovery functions

Other changes

N/A

Tested

It is tests

Related issues

• Fixes https://github.com/mento-protocol/mento-general/issues/43

Backwards compatibility

N/A

Documentation

N/A

[bayological]

@bowd This PR can be closed. Mento core repo has the latest McMint & this work has been migrated to a new branch based on the latest. https://github.com/mento-protocol/mento-core/pull/20