chore: dynamically pull ABI from upstream

[mfw78]

Problem

The ABI that is used to generate the contracts should not be duplicated in the repository, but instead consumed from upstream.

Solution

Add the contract's ABI via a dev dependency NPM package, and then use this for the typechain generation.

Blockers

• Upstream: feat: deployed abi json composable-cow#42
• NPM Package: chore: publish abi and deployment info composable-cow#60

[mfw78]

Will close this, and cow-sdk can choose explicitly which ABI to import. If required, an NPM package such as cowprotocol/composable-cow#60 can be used if requiring bulk ABI.