feat-mobile: add lang and theme settings

[paul-boegelsack]

Summary

Adds language and theme settings for stardust mobile.

Changelog

- Adds views for langauge and theme settings

Relevant Issues

Closes #5109
Closes #5110

Testing

Enable language and theme feature flags

Platforms

Please select any platforms where your changes have been tested.

• Desktop
  • MacOS
  • Linux
  • Windows
• Mobile
  • iOS
  • Android

Instructions

Please describe the specific instructions, configurations, and/or test cases necessary to test and verify that your changes work as intended.

...

Checklist

Please tick all of the following boxes that are relevant to your changes.

• I have followed the contribution guidelines for this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have added or modified tests that prove my changes work as intended
• I have verified that new and existing unit tests pass locally with my changes
• I have verified that my latest changes pass CI workflows for testing and linting
• I have made corresponding changes to the documentation

[begonaalvarezd]

👌🏼 lgtm