Implement version check to prevent old versions from making invalid changes

[SSchulze1989]

Description

Older Versions of the might work on Incompatible or Incomplete DTOs.
Mapping these to the DB can lead to invalidation of the Data and in worst case completely preventing another client from working with the data.

Multiple measures need to be taken to prevent this:

• Make sure no changes are submitted/accepted with non-matching versions
• Validating data before saving changes on db.

Work

After the first Major release the API must handle older versions in a non breaking way, but for now i think it is enough to just block all post and put request if the client version is older.

[SSchulze1989]

This issue is no longer relevant for now. Automatic updating of the tool is making sure only valid DTOs will be send.