feat(option): add optionNormalizeStrategies

[jiangshanmeta]

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when I write my vue plugin,I use custom properties in the options.But when I want to support different kind of option,for example ,both array and object,just like the props option, I found I have to write the normalize code in the mergeStrategy code, expecially considering of mixin condition.It seems wired and not good for reuse other merge strategy .What I do is to support extract the normalize code from merge code.

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