Transaction result subscription

[gordsport]

Front-end apps have accrued significant technical debt in managing the UI surrounding different transaction types.

Once a transaction is sent to a wallet different subscriptions and logic is needed to properly track the transaction and the resulting changes on the network.

As a result the TransactionResult bus event was added, but it only gets us part of the way there.

This work is to improve that or add a new subscription specifically for this purpose, so that you can easily track transactions and the changes that result from them.

This should also be beneficial in making it easier for external people to build on Vega

[mattrussell36]

I've put together a proposal of how this could look here: https://www.notion.so/vegaprotocol/Transaction-subscriptions-for-front-ends-75d6c18b2c96440387d8dfe6855d28bb?pvs=4

Please have a look. Open to any suggestions