Hook in workspace when vega gets tagged

[notbot00]

The Chore

Created a github action called .github/workflows/generate.yml, which ideally needs to be called when https://github.com/vegaprotocol/vega gets a new tag, so it regenerates all the bits needed for wallet-admin, wallet-client and transactions.
The transaction generation is not on the workflow file, that will need an extra step added with calling yarn nx run transactions:generate - this has some extra requirements tho, need the vega repo cloned and needs protoc to be installed in the container.