Improve download performance

[Hitenjain14]

Changes

Fixes

Tests

Tasks to complete before merging PR:

• [ ] Ensure system tests are passing. If not Run them manually to check for any regressions :clipboard:
• [ ] Do any new system tests need added to test this change? do any existing system tests need updated? If so create a PR at 0chain/system_test
• [ ] Merge your system tests PR to master AFTER merging this PR

Associated PRs (Link as appropriate):

• 0chain:
• gosdk: https://github.com/0chain/gosdk/pull/1271
• system_test:
• zboxcli:
• zwalletcli:
• Other: ... https://github.com/0chain/zs3server/pull/74

[codecov-commenter]

Codecov Report

Merging #1315 (7e91131) into sprint-1.11 (259c0cd) will increase coverage by 0.02%. The diff coverage is 100.00%.

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@@               Coverage Diff               @@
##           sprint-1.11    #1315      +/-   ##
===============================================
+ Coverage        23.74%   23.76%   +0.02%     
===============================================
  Files               87       87              
  Lines            10044    10047       +3     
===============================================
+ Hits              2385     2388       +3     
  Misses            7362     7362              
  Partials           297      297              

Flag	Coverage Δ
Unit-Tests	23.76% <100.00%> (+0.02%)	:arrow_up:

Flags with carried forward coverage won't be shown. Click here to find out more.

Files	Coverage Δ
...et/blobbercore/handler/object_operation_handler.go	17.25% <100.00%> (+0.20%)	:arrow_up: