Gladys Plus should upload backups in several chunks

[Pierre-Gilles]

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• If your changes affects code, did your write the tests?
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Description of change

Please provide a description of the change here. It's always best with screenshots, so don't hesitate to add some!

[relativeci]

Job #289: Bundle Size — 6.83MB (~+0.01%).

6a8030e vs 893eadd

Changed metrics (2/10)

Metric	Current	Baseline
Initial JS	2.94MB(~+0.01%)	2.94MB
Cache Invalidation	42.86%	0%

Changed assets by type (1/7)

	Current	Baseline
JS	4.92MB (~+0.01%)	4.92MB

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View Job #289 report on app.relative-ci.com

[codecov]

Codecov Report

Merging #1519 (338a113) into master (7e0b135) will decrease coverage by 0.01%.
The diff coverage is 97.18%.

@@            Coverage Diff             @@
##           master    #1519      +/-   ##
==========================================
- Coverage   96.58%   96.57%   -0.02%     
==========================================
  Files         617      618       +1     
  Lines        8935     8993      +58     
==========================================
+ Hits         8630     8685      +55     
- Misses        305      308       +3     

Impacted Files	Coverage Δ
server/api/controllers/gateway.controller.js	60.00% <0.00%> (ø)
server/config/scheduler-jobs.js	100.00% <ø> (ø)
server/utils/constants.js	100.00% <ø> (ø)
server/lib/gateway/gateway.init.js	79.31% <90.00%> (+3.11%)	⬆️
server/lib/gateway/gateway.backup.js	100.00% <100.00%> (ø)
server/lib/gateway/gateway.checkIfBackupNeeded.js	81.81% <100.00%> (-6.42%)	⬇️
server/lib/gateway/gateway.downloadBackup.js	92.85% <100.00%> (+0.26%)	⬆️
server/lib/gateway/index.js	100.00% <100.00%> (ø)
server/lib/index.js	94.87% <100.00%> (ø)
server/utils/readChunk.js	100.00% <100.00%> (ø)
... and 2 more

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