Remove DPPPT models

[ineiti]

Now that GAEN replaced the DPPPT code, all old code can be removed. This allows to stop taking care of this code.

Comments:

• '/v1' hello endpoint is not active anymore - is this a problem?

Closes #228

[ineiti]

Wait for the discussion in #228 before merging.

Hmm - nobody seems to care - let's remove this.

[ineiti]

So this moves the hello-endpoint from /v1 to /v1/gaen. I can also put it back to v1, but then I'd have to define a new controller.

[sonarcloud[bot]]

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96.9% Coverage
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