Add opening hours throughout the app

[jacqueline8711]

• add SSZ opening hours for financial aid + keep link to Student Financial aid (contact is ssz) in tuition fees screen
• show opening hours for all cafeterias

Related: #491, #1225

[i-walker]

Here are some Screenshots. On the updated Database integrated into the App.

My thoughts on the API:
We should specify where exactly each column is located.
I did this in my prototype with a primitive StringBuilder, so I would not break the legacy code.
I think we should rewrite these components.
Affected classes are:

• Location.kt
  //this should take a Json as an Input and populate the data class
• CafeteriaLocationImportAction.kt
• OpeningHoursDetailFragment.java
• OpeningHoursListActivity.java
• OpeningHoursDetailActivity.java
  //they load and display the Information of the Database. I think this will be deleted anyway