lockAndLoad does not check if the DataStore request was successful

[anthony0br]

https://github.com/ffrostfall/keyForm/blob/master/src/store/init.luau

lockAndLoad currently relies on a value successfullyLocked set during the transform function.

According to the Roblox documentation this transform function can be run any number of times, with the result discarded. The function running doesn't necessarily imply the data is successfully saved.

This means that in rare cases the method might silently fail to session lock a store.

successfullyLocked could be set to false at the top of the transform function and the result of the _updateAsync could be checked to ensure lockAndLoad always returns nil if setting the lock fails.