Feat: Handle non-ASCII account names better

[Nightblade]

Changed the .pasteFilter on import -> account name EditControl to URL-encode "non-ASCII" characters. Users can simply paste their account name as-is and hit Start.

This change eliminates the need to use www.urlencoder.org so I've removed the warning text and button.

Tested OK with:

쁘레따뽀르떼#4360

Old encoding:

%C3%AC%C2%81%C2%98%C3%AB%C2%A0%C2%88%C3%AB%C2%94%C2%B0%C3%AB%C2%BD%C2%80%C3%AB%C2%A5%C2%B4%C3%AB%C2%96%C2%BC%234360

New encoding:

%EC%81%98%EB%A0%88%EB%94%B0%EB%BD%80%EB%A5%B4%EB%96%BC%234360