feat(daemon): scale endpoint for flows & pods

[deepankarm]

• Separated the rolling_update & scale endpoints for Flows / Pods.
• Separated rolling_update & scale methods for JinaDClient.
• Removed UpdateOperation enums.
• Added unittests for scale store, partial-store & client.
• Added distributed tests for scale endpoints (Local Flow-remote Executor, Remote Flow, Remote Pod)

[codecov]

Codecov Report

Merging #3935 (8513cd4) into master (df57ce1) will increase coverage by 0.69%.
The diff coverage is 75.00%.

@@            Coverage Diff             @@
##           master    #3935      +/-   ##
==========================================
+ Coverage   88.34%   89.04%   +0.69%     
==========================================
  Files         180      180              
  Lines       12627    12629       +2     
==========================================
+ Hits        11155    11245      +90     
+ Misses       1472     1384      -88     

Flag	Coverage Δ
daemon	43.43% <25.00%> (+0.49%)	⬆️
jina	87.28% <75.00%> (+1.07%)	⬆️

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

Impacted Files	Coverage Δ
jina/peapods/runtimes/jinad/__init__.py	88.88% <75.00%> (+8.01%)	⬆️
jina/peapods/runtimes/zmq/asyncio.py	84.12% <0.00%> (-1.59%)	⬇️
jina/helper.py	83.27% <0.00%> (+0.17%)	⬆️
jina/peapods/pods/__init__.py	85.22% <0.00%> (+0.19%)	⬆️
jina/jaml/__init__.py	95.47% <0.00%> (+0.41%)	⬆️
jina/peapods/runtimes/zmq/zed.py	91.78% <0.00%> (+0.45%)	⬆️
jina/peapods/peas/__init__.py	85.10% <0.00%> (+0.53%)	⬆️
jina/peapods/zmq/__init__.py	90.46% <0.00%> (+0.69%)	⬆️
jina/clients/base/__init__.py	87.32% <0.00%> (+1.40%)	⬆️
jina/types/message/__init__.py	87.01% <0.00%> (+1.44%)	⬆️
... and 8 more

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[github-actions]

Latency summary

Current PR yields:

• 🐢🐢 index QPS at 1115, delta to last 2 avg.: -18%
• 🐢🐢 query QPS at 48, delta to last 2 avg.: -19%
• 🐢🐢 dam extend QPS at 32461, delta to last 2 avg.: -20%
• 🐢🐢 avg flow time within 1.5924 seconds, delta to last 2 avg.: +45%
• 🐎🐎🐎🐎 import jina within 0.551 seconds, delta to last 2 avg.: +22%

Breakdown

Version	Index QPS	Query QPS	DAM Extend QPS	Avg Flow Time (s)	Import Time (s)
current	1115	48	32461	1.5924	0.551
2.4.5	1219	52	36425	1.1153	0.5112
2.4.4	1502	66	45442	1.0742	0.3869

Backed by latency-tracking. Further commits will update this comment.

[JoanFM]

I am missing some unittests about the new scale endpoint