Layer table access for dashboard, imports, location layer

[dbauszus-glx]

It would be great to have a layer dashboard to generate a layer config. This can work either by setting up a query template which returns * fields from a table or by setting up a layer template with only a DBS and table defined. The dashboard itself is a view which will ingest the layer schema and provide utils to define a style object as well as infoj location schema. This will require the capability to access an object store through the provider endpoint.

[dbauszus-glx]

The hardest part which must be solved before the import is how to restrict access to a table without a layer configuration.

All layer requests are validated by the layer query module. To query layer data a valid layer object must be provided to the query template. Otherwise every user could query every table without restrictions.