randomString function
Generates a random string of the specified length using characters
from the given type.
Example:
print(randomString(5, CharacterType.lowerAlpha)); // Random lowercase string
Implementation
String randomString(int length, CharacterType type,
{AbstractRandomProvider? provider}) {
final range = characterRanges[type]!;
return String.fromCharCodes(List.generate(
length, (_) => randomBetween(range[0], range[1], provider: provider)));
}