Add Shared Method to Arrays

[mrjustaguy]

Describe the project you are working on

Various

Describe the problem or limitation you are having in your project

There are multiple instances where knowing if 2 arrays have any shared data would could be useful

Describe the feature / enhancement and how it helps to overcome the problem or limitation

Adding a Shared() method to Arrays would allow for very simple, single line checks if there is any identical data between 2 arrays.

Describe how your proposal will work, with code, pseudo-code, mock-ups, and/or diagrams

Array1=[0,1,2]
Array2=[0,4,5,6,7]
Array1.Shared(Array2) -> returns true

Array1=[0,1,2]
Array2=[3,4]
Array1.Shared(Array2) -> returns false

Implementation:
for i in range elements in array 1 iterate for j in range elements in array 2, if element i of array 1 == element j of array 2 return true, if iterations end and it didn't return true, return false

If this enhancement will not be used often, can it be worked around with a few lines of script?

Yes, one can make a function to do that that would take 6 lines of GDScript code (func, 2 for loops, if, 2 returns)

Is there a reason why this should be core and not an add-on in the asset library?

Array is core

[KoBeWi]

This is called intersection.
Duplicate of #1756