Fix function reloading

[bensku]

Description

Functions were validated too early in script reload process. To fix this, I added an API for reloading scripts that does it correctly. It might also be useful to addons!

I would appreciate if people with a lot of functions could test if this causes other problems.

---

Target Minecraft Versions: any
Requirements: none
Related Issues: #2802

[ShaneBeee]

I didn't have too many functions to test this out, but I had 1 function to test with.

Prior to this version:

I have a function in the file spiral.sk and im calling this function in test.sk
if I reload test its fine, if I reload spiral it throws this error:

[01:00:00 ERROR]: The function 'spiral' was deleted or renamed, but is still used in other script(s). These will continue to use the old version of the function until Skript restarts. (test.sk, line 12: loop spiral({_l}, 4, 8):')
[01:00:00 ERROR]: The function 'spiral' was deleted or renamed, but is still used in other script(s). These will continue to use the old version of the function until Skript restarts. (test.sk, line 12: loop spiral({_l}, 4, 8):')

Your PR:

I was able to reload each script without any issues 👍