Introduce function split() for strings

[sshymko]

Introduce counterpart to join() function for simple arrays where JSON format would be an overkill.

Usage example with dynamic jobs:

name: Dynamic jobs
on:
  workflow_dispatch:
    inputs:
      versions:   
jobs:
  deploy:
    runs-on: ubuntu-latest
    strategy:
      matrix:
        version: ${{ split(github.event.inputs.versions, ',') }}
    name: Deploy version ${{ matrix.version }}
    steps:
      - run: echo "hello world"

Sample input:

{
  "versions": "1,2,3"
}

[sshymko]

Would appreciate if someone could help to fix the compilation error:

The type or namespace name 'FilteredArray' could not be found

Or provide an example of how to return array from expression functions.
Can it simply return str.Split(separator) without EvaluationResult.CreateIntermediateResult()?

[76creates]

This is good fn addition, would be nice if we could get this ball rolling ⚡