Add Equinox.EventStoreDb - gRPC support

[bartelink]

This introduces a port of the Equinox.EventStore module entitled Equinox.EventStore.Grpc which:

• uses EventStore.Client.Grpc.Streams v 22.0.0

In doing this, the Equinox.EventStore package remains but:

• the Sample's integration tests shift to use the gRPC package instead
• is intended for use against server versions 21.10 and later, i.e. there is no logic to use V5 server compatibility mode etc
• references EventStore.Client v 22.0.0-preview

As part of the above, the guidance changes from running a local ESDB (v5) instance obtained via Chocolatey (on Windows) or brew (on MacOS) to using a 3 node cluster running under docker compose

related: #188

[bartelink]

This module should be renamed to Equinox.EventStoreDb (to disambiguate from Equinox.EventStore), which will continue to depend on EventStore.Client, (and align with EventStore's new consistent naming).

[bartelink]

Would love to see this implemented as it's abundantly clear that the gRPC interface is the only game in town going forward for EventStoreDB and simply makes sense to migrate to.

I don't have time to do this at present (and my current team I'm on are still on V5).

[dharmaturtle]

Hi! What would it take to complete this PR? When I diff EventSToreGrpc.fs with the main EventStore.fs, it isn't clear to me what's missing (other than the one TODO). Is it just updating the client to the LTS (20.10) and resolving the conflicts?

Edit: Ah - it doesn't compile.