Add New Script Helper Functions

[magicaldave]

Many customscripts written for tes3mp use large chunks of repeated code which are difficult to understand for new users and can also be handled by the engine. Related, but separate from #7 .

Merging this functionality into corescripts could be very useful in making the creation of custom scripts easier, such as @YvanCywan 's vectors library.

[YvanCywan]

This can be bundled with issue #8 as they cover the same scope.