Support ISo charset names without separation between ISO and 8859

[rsevero]

Is your feature request related to a problem? Please describe.
Just started using this package in a personal app. I am reading enconding names from files and in these files ISO encoding names for, for example, ISO 8859-3, are ISO8859-3 and not ISO-8859-3 or ISO_8859-3 as this package expects in Charset.getByName().

Describe the solution you'd like
Please support ISO charset names also without any separators between ISO and 8859: ISO8859-3 besides ISO-889-3 and ISO_8859-3.

Describe alternatives you've considered
I am manually regexing the encoding name to check if it starts with ISO and them including a hyphen between ISO and 8859 but it's cumbersome and shouldn't be necessary.

[shirne]

you can call

Charset.register(latin2, 'iso8859-2');
Charset.register(latin3, 'iso8859-3');
// etc.

to register encoding name manually