Feature/store frontend

[pschuermann97]

Reason for this PR:

• Store Frontend can display dummy baskets correctly but has a data format mismatch with the basket backend.
• Backend data format for the basket needs to be updated (@this-kramer)
• for this reason, the current state of the store frontend needs to be merged to develop (although store frontend is unfinished)

Checklist:

Select whatever applies:

• [x] Code Properly Formatted
• [x] Documented