Enable immediate language change without requiring restart

[Dusk-afk]

Implemented a solution to enable immediate language changes in the UI without requiring a restart. Made use of the provider package.

Issue Resolved:

Closes #72

Additional Context

Using the provider package, the current language selected is stored as an app's state. Later whenever this state is altered, the whole widget tree is forced to be redrawn. The functionality to remember the language change after a restart remains unchanged.

Demo

Submitter Checklist:

• [x] There is a ticket (#72) for my issue
• [x] Wrote a good PR/commit description
• [ ] Discussed about the issue with reviewers in Discussions, Issues or other platforms
• [x] Confirmed that the PR only includes changes related to my issue
• [x] Checked the PR locally: flutter build windows (Request it to reviewers if you're having problems)