[4.x] Delay watch functions to avoid loading race condition

[Jade-GG]

Depending on what order the code gets loaded in, these watch functions may be called before the variable exists. This throws an error and breaks all JS on the site.

For example, on a vanilla Rapidez installation this can happen with the useCart watch if you don't install rapidez/account. Possibly something to do with how useMask imports it---it's not entirely clear how the imports end up getting resolved under different circumstances.

Because we don't have exact control over when and how things get loaded in, the best solution I could find is to make the watch get executed later. This still works exactly as it should, but makes sure everything is loaded in before.

The one in useUser is probably unnecessary, but I've added it anyway to be safe.

[Jade-GG]

This seems to unfortunately not fix anything after all :(