[Numpy] Port nd.random.multinomial to npx.sample_categorical

[xidulu]

Description

#18270

Checklist

Essentials

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Changes

• Feature1, tests, (and when applicable, API doc)
• Feature2, tests, (and when applicable, API doc)

Comments

• If this change is a backward incompatible change, why must this change be made.
• Interesting edge cases to note here

[mxnet-bot]

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[sxjscience]

@xidulu How about moving it to npx.random.categorical to make it more consistent?

[xidulu]

@sxjscience

Done.

[zheyuye]

Currently this op and nd.sample_multinomial only accepting noralized probability as input, could we make it compatible with the log-odds like npx.random.bernoulli

[xidulu]

@mxnet-bot run ci [unix-cpu]

[mxnet-bot]

Jenkins CI successfully triggered : [unix-cpu]

[yzhliu]

good to me. thanks @xidulu @sxjscience