Add the history list (#12)

[plaeschu]

• Make non-final classes final

• Broken V1 of the history list

• Standardize viewmodel instantiation

• Improve history list view

• Add mock purchase service

• Beautify date time format

• Use default locale as speaker language

• Add user score fragment

• Add user score view model and view binding

• Combine user score and purchase list fragments

• Rearrange user score fragment

• Color user score

• Add additional mock purchases

• Color purchase entries