Further clean-ups and simplifications of smartimport-tests

Generalize redundant code into the template class.

Replace the o.e.pde.ui.tests.smartimport/pom.xml by the still required
pom.model. configuration in the build.properties (many properties were
obsolete anyway).

Follow-up on "Rewrite smartimport test as plain JUnit test"

ui/org.eclipse.pde.ui.tests.smartimport/META-INF/MANIFEST.MF

@@ -11,11 +11,14 @@ Require-Bundle: org.eclipse.core.resources,
  org.eclipse.swt,
  org.eclipse.ui.ide,
  org.eclipse.jdt.ui,
- org.eclipse.pde.ui
+ org.eclipse.pde.ui,
+ org.eclipse.pde.ui.tests,
+ assertj-core
 Bundle-ActivationPolicy: lazy
 Eclipse-BundleShape: dir
 Bundle-RequiredExecutionEnvironment: JavaSE-17
 Automatic-Module-Name: org.eclipse.pde.ui.tests.smartimport
 Import-Package: org.junit,
+ org.junit.rules,
  org.junit.runner,
  org.junit.runners

ui/org.eclipse.pde.ui.tests.smartimport/build.properties

@@ -11,6 +11,9 @@
 bin.includes = about.html,\
                .,\
                test.xml,\
-               META-INF/
+               META-INF/,\
+               resources/
 src.includes = about.html
 source.. = src/
+pom.model.packaging = eclipse-test-plugin
+pom.model.property.testClass = org.eclipse.ui.tests.smartimport.AllTests