Add a new "Upgrade" button to EE

[lathapatil]

Fixes : #1178

A new "Upgrade" button that allows to select the new EE, removes all old ones and updates the classpath in one go.

As part of this, this dialog should then be sorted by EE in descending order (highest EE first):

[github-actions[bot]]

Test Results

 36 files   -   170   36 suites   - 170   13s :stopwatch: - 35m 25s  26 tests  - 3 552   26 :white_check_mark:  - 3 476  0 :zzz:  -  76  0 :x: ±0  144 runs   - 7 258  144 :white_check_mark:  - 7 104  0 :zzz:  - 154  0 :x: ±0 

Results for commit 4d304ba6. ± Comparison against base commit 75583bc2.

This pull request removes 3552 tests.

``` AllPDETests org.eclipse.pde.core.tests.internal.AllPDECoreTests org.eclipse.pde.core.tests.internal.DependencyManagerTest ‑ testFindRequirementsClosure_importPackage AllPDETests org.eclipse.pde.core.tests.internal.AllPDECoreTests org.eclipse.pde.core.tests.internal.DependencyManagerTest ‑ testFindRequirementsClosure_includeFragments AllPDETests org.eclipse.pde.core.tests.internal.AllPDECoreTests org.eclipse.pde.core.tests.internal.DependencyManagerTest ‑ testFindRequirementsClosure_includeFragmentsProvidingPackages AllPDETests org.eclipse.pde.core.tests.internal.AllPDECoreTests org.eclipse.pde.core.tests.internal.DependencyManagerTest ‑ testFindRequirementsClosure_includeNonTestFragments AllPDETests org.eclipse.pde.core.tests.internal.AllPDECoreTests org.eclipse.pde.core.tests.internal.DependencyManagerTest ‑ testFindRequirementsClosure_includeOptional AllPDETests org.eclipse.pde.core.tests.internal.AllPDECoreTests org.eclipse.pde.core.tests.internal.DependencyManagerTest ‑ testFindRequirementsClosure_requireBundle AllPDETests org.eclipse.pde.core.tests.internal.AllPDECoreTests org.eclipse.pde.core.tests.internal.DependencyManagerTest ‑ testFindRequirementsClosure_requireBundle2 AllPDETests org.eclipse.pde.core.tests.internal.AllPDECoreTests org.eclipse.pde.core.tests.internal.DependencyManagerTest ‑ testFindRequirementsClosure_requireDifferentVersions AllPDETests org.eclipse.pde.core.tests.internal.AllPDECoreTests org.eclipse.pde.core.tests.internal.DependencyManagerTest ‑ testFindRequirementsClosure_requiredCapability AllPDETests org.eclipse.pde.core.tests.internal.AllPDECoreTests org.eclipse.pde.core.tests.internal.WorkspaceModelManagerTest ‑ testBundleRootHandling_bundleRootChangedFromDefaultToOthersAndReverse … ```

:recycle: This comment has been updated with latest results.