Move network requests to ViewClient

[bowenwang1996]

Fixes #1926

[codecov]

Codecov Report

Merging #1955 into staging will decrease coverage by 0.03%.
The diff coverage is 95.83%.

@@             Coverage Diff             @@
##           staging    #1955      +/-   ##
===========================================
- Coverage    86.61%   86.57%   -0.04%     
===========================================
  Files          167      167              
  Lines        31517    31618     +101     
===========================================
+ Hits         27297    27372      +75     
- Misses        4220     4246      +26

Impacted Files	Coverage Δ
core/primitives/src/views.rs	60.34% <100%> (+0.2%)	⬆️
core/primitives/src/merkle.rs	100% <100%> (ø)	⬆️
core/primitives/src/block.rs	97.11% <92.85%> (+0.08%)	⬆️
chain/chain/src/test_utils.rs	79.88% <0%> (-4.25%)	⬇️
chain/client/src/client.rs	92.98% <0%> (-1.35%)	⬇️
chain/client/src/types.rs	82.03% <0%> (-0.79%)	⬇️
chain/chain/src/validate.rs	90.87% <0%> (-0.37%)	⬇️
chain/network/src/peer_manager.rs	76.94% <0%> (-0.15%)	⬇️
...enesis-tools/genesis-csv-to-json/src/serde_with.rs	100% <0%> (ø)	⬆️
runtime/runtime/tests/test_evil_contracts.rs	100% <0%> (ø)	⬆️
... and 22 more

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