Add back UI test-harness and required tests to Eclipse P2-repository

[HannesWell]

Add back the tests other tests depend on.

Follow-up on

• [Build] Remove test Plug-ins from Eclipse P2-repository #3772

The missing test Plug-ins where identified by building all submodules locally against a local build of the Eclipse p2-repository.

[HannesWell]

The test projects that have dependencies on other tests from other git submodule repositories are (not listing test interdependencies within the same repository):

• https://github.com/eclipse-pde/eclipse.pde/blob/50600c6050f88fba8ecdb828ef55e47ece8b6912/apitools/org.eclipse.pde.api.tools.tests/META-INF/MANIFEST.MF#L19
• https://github.com/eclipse-jdt/eclipse.jdt.ui/blob/90d2d96818a5025bc2ff73e548a64021c9acc163/org.eclipse.jdt.text.tests/META-INF/MANIFEST.MF#L33
• https://github.com/eclipse-jdt/eclipse.jdt.ui/blob/90d2d96818a5025bc2ff73e548a64021c9acc163/org.eclipse.jdt.ui.tests/META-INF/MANIFEST.MF#L71
• https://github.com/eclipse-jdt/eclipse.jdt.ui/blob/90d2d96818a5025bc2ff73e548a64021c9acc163/org.eclipse.jdt.text.tests/META-INF/MANIFEST.MF#L34
• https://github.com/eclipse-jdt/eclipse.jdt.ui/blob/90d2d96818a5025bc2ff73e548a64021c9acc163/org.eclipse.jdt.text.tests/META-INF/MANIFEST.MF#L35

Generally speaking, it would probably the best to avoid these test interdependencies and e.g. move relevant shared code into the 'harness' utilities or alike and remove the test projects again.

[HannesWell]

The failure in baseline comparison is now handled in

• Baseline comparision failes for tests removed from Eclipse P2-repository #3784

Submitting this nevertheless now and will start another I-build to unblock the target-platform resolution (and builds without baseline check) for PDE and JDT-UI (see list of problems above).