Remove requirement of a contract address on ListEvents

[kroggen]

Currently the Aergo GRPC ListEvents and ListEventStream services require a contract address in the FilterInfo for they to work.

We are needing to list all events from a specific block and the above limitation is not allowing this.

When one contract is called, it can call other contracts and they can call others... and any of these contracts can emit events. An ARC1 token can be the last to be called, and we need to catch events from all the contracts.

Proposal

Remove the requirement of a contract address on ListEvents GRPC service, and list all events in the supplied block range

The same can be applied to the ListEventStream service, being able to listen to all events from the blockchain

Later

When doing this on the server side, we need also to update the clients:

• aergocli
• herajs
• herapy
• heraphp
• libaergo

[kroggen]

This is no longer a priority.

If someone finds it is a requirement, please reopen the issue