Support for non utf-8 chars in username field.

[i128]

Right now when a user submits a hashfile where the username contains a non utf-8 character (åøß e.g.) hashview cannot parse it correctly. Two potential fixes:

1. hex/base64 encode user names:
   Pro: allows for quick solution
   Con: Harder to do case insensitive searches.

2. Convert database language support to handle non utf-8 characters
   pro: allows for case insensitive searchs
   con: might require table migrations for existing hashfiles

if we go with second solution we should probably convert the hashes table too while we're at it.

[i128]

http://www.herongyang.com/PHP/Non-ASCII-MySQL-Store-Non-ASCII-Character-in-Database.html
https://adamhooper.medium.com/in-mysql-never-use-utf8-use-utf8mb4-11761243e434