* Add idxmin() which returns the index of the minimum value
* Add idxmax() which returns the index of the maximum value
* Add tests for idxmin()
* Add tests for idxmax()
* Remove initialization of result = 0
* Adds overloading for arrays (no enums indexed arrays yet)
* Add support for enum index arrays
* Fix tests with enum
* Fix tests for idxmax
* Change names of the procedures to minIndex and maxIndex
* address Araq's comments:
- remove 'array' versions
- add .since pragma
- return 'int' instead of 'Natural'
- add changelog entry
Co-authored-by: Federico A. Corazza <20555025+Imperator26@users.noreply.github.com>