LPS-48307 Splitting value from sole element so empty string results in empty array

hey @brianchandotcom,

As you may recall (https://github.com/brianchandotcom/liferay-portal/pull/19771), I removed the string splitting logic from ``ParamUtil.getParameterValues(HttpServletRequest request, String param, String[] defaultValue)`` because it was causing ``LPS-48085`` and because it didn't make sense to always try to split a string by a comma. It was not clear for those who were using the API.

This caused ``LPS-48307`` and @brandizzi came up with a solution that only splits the values for ``int``, ``long``, ``boolean`` and so on. It's safer because those values shouldn't have a comma in it and it keeps backwards compatibility (for most cases).

What do you think?

Thx,