tonic-build: Builder: add {enum,message}_attributes

[g0hl1n]

Motivation

The latest prost-build introduced enum_attribute and message_attribute configurations. We should support it.

Solution

Update prost-build to v0.11.6 and add the enum_attribute and message_attribute forwarders.

[LucioFranco]

Should probably add message attribute as well? tokio-rs/prost@14ac71e#diff-702d1c883416266db565804e8243178a5e3b59e9c22dff7d3161247d13aad208R502

[g0hl1n]

ACK. Will update the PR accordingly.

[LucioFranco]

Thanks!

[g0hl1n]

Forgot to run cargo fmt on the message_attributes patch. I've updated the PR. Sorry for missing it on the first try.

[Hallot]

Thank you g0hl1n.
@LucioFranco Would it possible to have a new release soon with this feature? That would be most appreciated, thank you.

[dado0583]

+1. Would love to use this to add the derive_builder to the message generated code so that I can generate protos without explicitly providing every field (https://crates.io/crates/derive_builder)

Is there anything I can do to help get the release out @g0hl1n ?

(cc @samiam376)

[LucioFranco]

It might be a bit to get a release out I believe there are some breaking changes on master and I am traveling over the next few weeks (and was just travelling). So I will need some time to sort that out. Sorry about that.