Speeddial: decode initialScript data as Utf8
Summary:
BUG: 406095
Solution based on:
https://developer.mozilla.org/en-US/docs/Web/API/WindowBase64/Base64_encoding_and_decoding#Solution_4_%E2%80%93_escaping_the_string_before_encoding_it
Test Plan: Add webpage with title which contains Utf8 character (e.g. ľščťžýáíéúäô) into speeddial
Reviewers: Falkon, drosca
Reviewed By: Falkon, drosca
Subscribers: falkon, drosca
Tags: Falkon
Differential Revision: https://phabricator.kde.org/D27081