(5/5) Create new display unit on setup

[andr9528]

• Single Responsibility principle
• Open/Close principle
• Liskov's substitution principle
• Interface segregation principle
• Dependency inversion principle

Will be done in branch called 'ClientSprintOne'

Task:

• Created SD over the Initialization of the display unit.
• Create Method Prologs over the Initialization method.
• Code the Initialization of the display unit.
• Test if the Initialization works as expected.

[andr9528]

Client will succesfully create itself in the database on first run.

[Kristiansax]

Shares the same issues as #46