imp(rpc,server): concurrent gRPC queries

[yihuang]

Closes: #1007

Description

• Initiate the GRPCClient introduced in sdk 0.46.

Verified manually that it indeed worked (by adding a long sleep in one of the grpc query handlers).

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[fedekunze]

ACK.

Verified manually that it indeed worked (by adding a long sleep in one of the grpc query handlers).

Does this need any additional documentation? Would be nice to add some concurrent query test cases in the JSON-RPC

[yihuang]

ACK.

Verified manually that it indeed worked (by adding a long sleep in one of the grpc query handlers).

Does this need any additional documentation? Would be nice to add some concurrent query test cases in the JSON-RPC

may need a very slow debug_traceTransaction call, slow enough to slow down block production, to notice the effect though. most queries run pretty fast even if sequentially.

[fedekunze]

@yihuang can you look into the failing integration tests?

[codecov]

Codecov Report

Merging #1352 (9487a0d) into main (34226aa) will not change coverage.
The diff coverage is 0.00%.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #1352   +/-   ##
=======================================
  Coverage   54.77%   54.77%           
=======================================
  Files         107      107           
  Lines        9994     9994           
=======================================
  Hits         5474     5474           
  Misses       4249     4249           
  Partials      271      271           

Impacted Files	Coverage Δ
x/evm/keeper/grpc_query.go	69.06% <0.00%> (ø)

[yihuang]

@yihuang can you look into the failing integration tests?

Integration test fixed, but the panic causing node to crash need further investigation, probably at sdk level