Improve region settings for processing

[linakrisztian]

The importer should be able to set a region:

• the region should be set with extent="spatial" (see https://github.com/actinia-org/actinia-core/blob/main/tests/test_async_processing_import_export.py#L367-L374 )
  • the importer will then set the region before executing the r.import (thus can also be used for ephemeral processing --> will be written in PC)
  • if no extent given, the current set region will be used
• This will be analogue to r.import with extent=region. For persistent processing the region can be set in advance, for ephemeral processing it has to be done in a previous step --> see also next section "Related to this"

Related to this:

• For persistent processing the set region is not merged
• This should be changed e.g. here: https://github.com/actinia-org/actinia-core/blob/main/src/actinia_core/processing/actinia_processing/ephemeral/persistent_processing.py#L308
• Note: will this be an API breaking change?