Add endpoint for querying estimated pool share

[codecov[bot]]

Codecov Report

Merging #3377 (f378dd8) into master (482802e) will increase coverage by 0.10%. The diff coverage is 85.36%.

@@            Coverage Diff             @@
##           master    #3377      +/-   ##
==========================================
+ Coverage   43.20%   43.30%   +0.10%     
==========================================
  Files         166      166              
  Lines       15833    15874      +41     
==========================================
+ Hits         6840     6875      +35     
- Misses       8582     8586       +4     
- Partials      411      413       +2     

Impacted Files	Coverage Δ
x/clp/keeper/grpc_query.go	71.95% <85.36%> (+2.68%)	:arrow_up: