feat: return result from flow and client

[hanxiao]

add return_results (by default = False) in client CLI, so that when turning on, results are returned as a list. Can be used with Flow and AsyncFlow, e.g.

AsyncFlow:

with AsyncFlow(return_results=True).add() as f:
    r = await f.index_ndarray(np.random.random([10, 2]))
    assert isinstance(r, list)
    assert isinstance(r[0], Response)

SyncFlow

with Flow(return_results=True).add() as f:
    r = f.index_ndarray(np.random.random([10, 2]))
    assert isinstance(r, list)
    assert isinstance(r[0], Response)

Design decision:

• dropping asyncio generator. Complicated, can not unify the Sync & AsyncFlow interface in short time.
• people who wants to use this function is more likely to fetch all result at once, otherwise, on_done callback is sufficient.
• complicated usage e.g. fully delegating async generator to users is possible, but sounds overengeering to me atm, can be future work. Out of scope of this PR.

[github-actions]

This PR closes: #1540

[github-actions]

This PR closes: #1540

[JoanFM]

would it make sense to return a generator to make it more general?

[hanxiao]

tried. too complicated., async generator is depreciated in python asyncio

[hanxiao]

also, if async generator is desired, why not directly use on_done?

[hanxiao]

see design decision in PR body

[JoanFM]

that is true. Just a comment that felt more natural, but no big deal

[github-actions]

Latency summary

Current PR yields:

• 😶 index QPS at 1858, delta to last 3 avg.: +0%
• 😶 query QPS at 32, delta to last 3 avg.: -4%

Breakdown

Version	Index QPS	Query QPS
current	1858	32
0.8.13	1851	32
0.8.12	1850	32
0.8.11	1852	35

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

[codecov]

Codecov Report

Merging #1541 (4a481c0) into master (822d075) will increase coverage by 0.09%.
The diff coverage is 60.86%.

@@            Coverage Diff             @@
##           master    #1541      +/-   ##
==========================================
+ Coverage   84.42%   84.51%   +0.09%     
==========================================
  Files         108      108              
  Lines        6305     6368      +63     
==========================================
+ Hits         5323     5382      +59     
- Misses        982      986       +4     

Impacted Files	Coverage Δ
jina/proto/serializer.py	100.00% <ø> (ø)
jina/flow/asyncio.py	68.29% <12.50%> (ø)
jina/clients/asyncio.py	75.00% <33.33%> (ø)
jina/clients/base.py	80.00% <100.00%> (+1.21%)	⬆️
jina/clients/helper.py	79.03% <100.00%> (+0.34%)	⬆️
jina/parser.py	86.44% <100.00%> (+0.03%)	⬆️
jina/logging/sse.py	91.42% <0.00%> (-3.89%)	⬇️
jina/logging/profile.py	68.33% <0.00%> (-0.58%)	⬇️
jina/flow/base.py	88.52% <0.00%> (-0.43%)	⬇️
jina/executors/decorators.py	90.75% <0.00%> (-0.16%)	⬇️
... and 16 more

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