[Core: Utility] Remove asArray function

[johnsaigle]

Brief summary of changes

asArray() had a cleanup tag about deleting it and replacing its calling code with toArray instead since the functions are basically equivalent.

[HenriRabalais]

looks good!

[kongtiaowang]

php lorisform_parser.php
PHP Fatal error: Uncaught TypeError: Return value of Utility::toArray() must be of the type array, string returned in /var/www/loris/php/libraries/Utility.class.inc:491

[johnsaigle]

Upon further review, these functions actually have quite different behaviour.

• toArray() takes array|string. When given an associative array (i.e. one that does not have 0 as an array key) it returns a new numeric array containing the associative_array as its first element. IN the case of numeric arrays or strings, they simply get returned to the calling code unchanged.

• asArray() converts scalar values to arrays, and returns arrays.

We can take two approaches here:

1. Update the function docs to make these distinctions clear. At the very least we need to remove the cleanup note about asArray()
2. Do a deeper refactor:
   • Change toArray() to toNumericArray() and ensure that only associative arrays are passed as parameters. Use TypeErrors or DeprecatedExceptions to prevent calling code from passing scalar values.

Thanks to @xlecours and @kongtiaowang for doing testing on this. @xlecours @driusan Do you have a preference as to what approach to use here?

[driusan]

I prefer simplifying if possible (so approach #2), personally.. but you can always start by improving the docs

[johnsaigle]

Closing this PR in favour of #4151