simulation: Add weighted operation

[ValarDragon]

The intent of this is to reduce the amount of proposals submitted, to speed up the simulation a bit. At the moment there are too many calls, so its overly computationally intensive. (Especially as each proposals schedules ~50 votes)

This also reduces the number of msg edit validators, since I don't think thats a useful thing for the fuzzer to be spending cycles on.

• Targeted PR against correct branch (see CONTRIBUTING.md)

• Added entries in PENDING.md with issue #

• rereviewed Files changed in the github PR explorer

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• Reviewers Assigned
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[codecov]

Codecov Report

❗ No coverage uploaded for pull request base (develop@fb0cc0b). Click here to learn what that means.
The diff coverage is n/a.

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[cwgoes]

This is great but I'm going to wait a bit to merge so the existing failing simulation cases we have don't change.

[cwgoes]

Merging #2238 so we can merge this now.

[cwgoes]

utACK