refactor: add MigrateHandler to allow reuse migrate genesis related function (backport #17296)

[mergify]

This is an automatic backport of pull request #17296 done by Mergify.
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	both modified:   CHANGELOG.md
	both modified:   x/genutil/client/cli/migrate.go

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[mmsqe]

@julienrbrt seems we need to use migrations or pass as cb

[julienrbrt]

Right!