Disable the default features of the tonic and tonic-build crates to allow downstream consumers to build in Wasm

[willemolding]

Closes #1269

Note this regenerates the code-generated proto/service.rs file and the newer version is included in this PR. This is a minor change to the zcash_client_backend public API as these are exposed.

[str4d]

Thanks for the PR!

[str4d]

Also, in addition to making the above change, add the following change to .github/workflows/ci.yml so we are testing this change:

diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 6263019a6..ebf418cfe 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -195,7 +195,7 @@ jobs:
         run: cargo add --no-default-features --path ../crates/zcash_proofs
       - name: Add zcash_client_backend as a dependency of the synthetic crate
         working-directory: ./ci-build
-        run: cargo add --no-default-features --path ../crates/zcash_client_backend
+        run: cargo add --features lightwalletd-tonic --path ../crates/zcash_client_backend
       - name: Copy pinned dependencies into synthetic crate
         run: cp crates/Cargo.lock ci-build/
       - name: Add target

[willemolding]

Thanks for the review @str4d !

I moved the impl of CompactTxStreamerClient<tonic::transport::Channel> to proto.rs as suggested but put it behind just a feature flag without a target_arch check.

I think this makes more sense as it it feels a little weird to have the API change depending on the build target. Instead builds will fail if the feature is enabled and then Wasm builds can disable it to have it work. I think more useful information is communicated this way.

[str4d]

Reviewed 61447d9

[codecov]

Codecov Report

Attention: Patch coverage is 0% with 2 lines in your changes are missing coverage. Please review.

Project coverage is 63.42%. Comparing base (1c72b0b) to head (d702aea).
Report is 11 commits behind head on main.

Files	Patch %	Lines
zcash_client_backend/src/proto.rs	0.00%	2 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1270      +/-   ##
==========================================
- Coverage   63.55%   63.42%   -0.13%     
==========================================
  Files         121      121              
  Lines       13661    13705      +44     
==========================================
+ Hits         8682     8693      +11     
- Misses       4979     5012      +33     

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