Function transformAndEnsureRegExpRegExpArray

Transforms a string or an array of strings into an array of regular expressions, ensuring that the result is always an array.

This function accepts a value that may be a single string, an array of strings, or undefined. It then:

• Converts each string into a RegExp object.
• If the input is an array containing nested arrays, it converts each string in the nested arrays into RegExp objects.
• Ensures that the result is always an array of RegExp objects or arrays of RegExp objects.