added new features to the endpoints; changed management of AAI; fixes for post/patch of data

'role' can be used as a fields-argument with the search endpoint (related to #145 (closed))

The stationmeta endpoint can have fields-arguments from globalmeta (and uses pydantic, related to #144)

correct version format is inserted when patching and posting bulk data and the bug in posting bulk data has been fixed (related to #142)

use new auth_user table after authorization and replaced/reduced auth_user table (related to #143)