[Feature] Let the user enter/add new items to the list/database

[hunnihundert]

⚠️ Is your feature request related to a problem? Please describe

The user should be able to enter (new) items to his/her list (and therefore to the database)

💡 Describe the solution you'd like

An EditText field in which the user can enter the desired item with suggestions ordered by popularity while the user is typing as discussed in the slack channel.

Designs

• Design: e.g. Figma URL
• Screenshots / Videos:

Other platforms involved

• iOS
• Backend