The existing implementation based on all runtime dependencies from OSGi
state reported too many projects as dependent, potentially causing build
cycles.

For example:
* all dependencies of a fragment were merged into the dependencies of
  its host
* Require-Capability is not relevant for build order

The new implementation mirrors RequiredClasspathContainer more closely
and only reports the following items as dependent:
* required bundles
* imported packages
* fragment host

ApiBaseline::getPrerequisiteComponents has been modified to use the same
logic. ::getDependentComponents probably would have been no longer
symmetric after this change. The method has been removed, as it wasn't
used outside of tests.


Change-Id: Ie5345e06a6e8a4823fb5e0601ad36fdfa3c4ff19
Signed-off-by: Julian Honnen <julian.honnen@vector.com>