Update color theme & logo

[antonyharfield]

Goal: update the Uploader branding to match the February arbimon.org launch

Suggested changes:

• All logos to new Arbimon logo (inside the app and the app icon)
• Poppins font everywhere (avoid using ABCFavorit because it might cause sizing issues)
• New color scheme matching arbimon.org

Notes:

• Avoid changes that will affect layout

[koonchaya]

• [ ] Update RFCx logo to Arbimon on Arbimon uploader icon to one of these icons https://drive.google.com/drive/folders/1k6_EvPjTnFpDqdCyfWeTtC3n_ANuvr1f?usp=sharing