Variability: Fix bug with "Adapt to extended configuration"

[dbinkele]

fixes #1724

[kbirken]

Here are my findings:

• The problem described can still be reproduced. When running the "Adapt this configuration to the extended configuration" intention on the extending configuration, the attributes are set to manual (although they should be inherited). This happens independent of the owning feature in the abstract config being selected or untouched.
• In the variability sandbox, you killed the HomeNetworkFeatures examples. Please re-instantiate it. All references in the Configuratons chunk are currently broken and the feature models HomeNetwork and Power have been deleted.
• CHANGELOG should be updated.

Pls. also fix dirty files, squash commits and finally merge from mps20241.

[dbinkele]

@kbirken Please have a look once more. If all is OK, I can squash the whole thing

[kbirken]

• The problem described can still be reproduced. When running the "Adapt this configuration to the extended configuration" intention on the extending configuration, the attributes are set to manual (although they should be inherited).

This is fixed now. However, if after this test the value of an attribute in the abstract config is being changed, then the same attribute in the extending configuration will not get the new inherited value (neither automatically nor by running the "Adapt..." intention). This can be tested with the AttrPlay sandbox model.

This issue wasn't mentioned in the ticket, but probably it hasn't been visible before due to the previous problem. But I believe it should also be fixed in this PR.

[dbinkele]

@kbirken your finding has been addressed