[Feature] User preference for initial translation language pair

[AmitMY]

Problem

Every user entering the app sees English->United States for translation, and needs to select a language, even if they:

• Are not using an English language browser
• Have previously modified the translation language

Description

1. We should use navigator.language as the initial language and country. he-IL should be Hebrew to Israel
2. We should store the last selected language/country pair, and use them initially if we do have them.
3. We should modify the current browser URL after a selection, to reflect the selected language and country. This will make the translation more shareable.