Fix bug in reload mode equality check. Better equality conversion for state variables

[freddyaboulton]

Description

Closes #8384

Fixes the linked issue specific reload mode. But the equality check for state, basically current_state != old_state would throw an error for some types like numpy/dataframe. So proposing a function to handle that case.

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Fix bug in reload mode equality check. Better equality conversion for state variables

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[aliabid94]

Oh I'm hesitant about this one. The reason why reactive code blocks in svelte don't automatically do deep equality checks with lists/objects is that it could be extremely expensive accidentally. The problem in this PR is that we are going to be doing deep checks on any state change at all, even if there's no change event listener attached to the state object.

let developers define their own state equality check function

I think it is very likely that developers will see their performance degrade and not have any idea why this is happening.

I don't mind the deep check in reload mode, it's okay if we add lag on reload, but I'd feel more comfortable using deep checks for state changes only if we also only do state change checks if there is a change event listener for the state variable. That way the deep check is only happening when explicitly requested to.

[freddyaboulton]

Thank you @aliabid94 @abidlabs for the reviews!!