fix(toRefs): don't trigger unwanted watchEffects

[wvffle]

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Description

This one is hard to tackle because of #885. The functionality here is kind of exclusive with the bug that this PR aims to fix.

This PR introduces ToRefsOptions property with a replaceRef boolean flag. By default, the flag is set to true to prevent breaking changes. If replaceRef is true, and one of the returned toRefs ref is changed, the original ref object is replaced by a copy. If the flag is set to false, only a key of the original ref is updated.

fixes #3258

Additional context

I couldn't come up with a better name. Maybe deep would better resemble that.

Another solution that I thought of would be to check if objectRef.constructor.name === 'RefImpl' and if so, update only the key. Vue has no system (that I know of) of distinguishing between Ref, ComputedRef and CustomRef, so that solution seems a bit hacky and is prone to changes of Vue internals. Also it makes toRefs kind of unpredictable when used with other composables.

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🤖 Generated by Copilot at 59632ac

Added a new feature to the toRefs function to optionally replace the original ref with a copy on property update. This can help avoid unwanted side effects when using toRefs with reactive objects. Updated the tests and the documentation accordingly.

🤖 Generated by Copilot at 59632ac

• Add ToRefsOptions interface to define the type of the optional parameter for the toRefs function (link)
• Modify toRefs function signature to accept an options parameter with a default value of an empty object (link)
• Destructure the options parameter and assign a default value of true to the replaceRef variable (link)
• Change the set function of the computed property to check the value of the replaceRef variable and either replace the original ref with a copy or mutate it directly on property update (link)
• Import watchSyncEffect function from vue-demi in toRefs/index.test.ts (link)
• Add two new tests to check the behavior of the toRefs function with different values of the replaceRef option (link)