Bug fix: Removes length limit (of TLD) when validating a hostname

The regular expression matching a tld in a hostname was limited to 2 to 10 chars.
This limit was reached with new gTLDs like .photography. Added this use case to
tests and removed length limit of 10 chars to allow new TLDs like .photography.
Set fixed length limit for validating TLDs in hostname validator.
Merge branch 'hotfix/#5992-remove-tld-length-limitations'

Close #5992