Integrate go-commp-utils

[dirkmc]

Fixes filecoin-project/lotus#4899

Note: Depends on changing the go-state-types version in go-commp-utils go.mod to match the one in go-fil-markets:
github.com/filecoin-project/go-state-types v0.0.0-20200928172055-2df22083d8ab

[codecov-io]

Codecov Report

Merging #452 (87199e6) into master (9ab6adb) will decrease coverage by 0.19%.
The diff coverage is 0.00%.

@@            Coverage Diff             @@
##           master     #452      +/-   ##
==========================================
- Coverage   65.20%   65.01%   -0.18%     
==========================================
  Files          47       46       -1     
  Lines        3229     3152      -77     
==========================================
- Hits         2105     2049      -56     
+ Misses        880      871       -9     
+ Partials      244      232      -12     

Impacted Files	Coverage Δ
retrievalmarket/impl/provider_environments.go	63.64% <ø> (ø)
storagemarket/impl/client.go	20.16% <ø> (ø)
storagemarket/impl/clientutils/clientutils.go	40.00% <ø> (ø)
storagemarket/impl/provider.go	27.41% <0.00%> (-0.51%)	⬇️

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[hannahhoward]

LGTM.