Reject wasm zips exceeding limit

[alpe]

Resolves #287

[codecov]

Codecov Report

Merging #301 into master will increase coverage by 0.05%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##           master     #301      +/-   ##
==========================================
+ Coverage   17.23%   17.29%   +0.05%     
==========================================
  Files          35       35              
  Lines       10463    10468       +5     
==========================================
+ Hits         1803     1810       +7     
+ Misses       8563     8562       -1     
+ Partials       97       96       -1     

Impacted Files	Coverage Δ
x/wasm/internal/keeper/ioutil.go	100.00% <100.00%> (ø)
x/wasm/internal/keeper/keeper.go	90.21% <0.00%> (+0.61%)	⬆️

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[alpe]

Included in #302