feat: automatically generate transaction batch

[mfw78]

Problem

It's frustrating using this setup that after settings have been modified, a transaction batch needs to be created to be submitted to the CoWDAO Safe. This is currently a manual process, and subject to possible error.

Suggested solution

During the CI/CD, calculate the IPFS hash (CID) that will be generated and automatically populate the transaction batch with the correct IPFS hash for the snapshot TXT record.

This transaction batch could be part of the artifacts that are generated during the release process that is automatically triggered on merge to main.

Alternatives considered

Manually creating the transaction batch, though this is subject to error.

Additional context

An example of how to generate the transaction batch JSON can be found here (credit: @fedgiac)

Acceptance criteria

On merge to main:

• settings.json is automatically uploaded and pinned on
• batch.json, a safe transaction batch is automatically created for updating CoWDAO