toKebabCase should remove diacritics of characters

[necrifede]

When there is a character with diacritics it should be converted to the base character

It is necessary when using different languages

> R_.toKebabCase('Adiós  amigo Español')
"adios-amigo-espanol"

> R_.toKebabCase('Tschüss Freund')
"tschuss-freund"