Make benchmark arguments more flexible

[Padarn]

This is currently WIP - I needed this locally to make it possible to modify these arguments in the benchmarks. If people like the suggested format I will apply this to all benchmarks.

Note because some argument are list and some are lists of lists, you would need to do

python loader/neighbor_loader.py --hetero-neighbor_sizes 5 5 --hetero-neighbor_sizes 10 10

and

python loader/neighbor_loader.py --batch-sizes 1 10 20

[codecov]

Codecov Report

Merging #4862 (84ab29b) into master (15a6fff) will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master    #4862   +/-   ##
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  Coverage   82.71%   82.71%           
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  Files         330      330           
  Lines       17887    17887           
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  Hits        14795    14795           
  Misses       3092     3092           

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[rusty1s]

Can you clarify? Wouldn't it be easier to just pass in a list of lists? No strong opinion though :)

[Padarn]

Wouldn't it be easier to just pass in a list of lists?

Hmm, maybe I misunderstood how it was meant to be used before. Using argparse I couldn't find an obvious way to pass a list of lists, except using the approach given in this MR.

[Padarn]

Curious if anyone else has opinions on this? @mszarma you were the github suggested reviewer

[mszarma]

Hi @Padarn and @rusty1s , using list of list with argparse is not so easy but i believe there is some way to do that, here is some POC for you: Padarn#1
Please let me know if that something that meets your needs.

[Padarn]

I think your idea makes sense, let me integrate your change. Thanks!

[Padarn]

Thanks for the suggestion @mszarma - have modified this PR