change environment parameters

[d047491]

I would like to change the env parameter definition in our early phase now:

• I want to decouple AMS_SERVICE from the rest of the parameters, as it should be possible to define, without triggering a bas DCL upload
• AMS_DATA.directories got removed and the BP scans automatically
• not AMS_DATA consists only of root. So I propose to move away from the json type and introdude AMS_DCL_ROOT, which triggers upload and defines DCL position
• If you want more parameters in future we will introduce them with AMS_ prefix

[jkbschmid]

Concept sounds good, but I think tests should be adapted to reflect it (remove AMS_DATA from tests and replace with other config vars).