Migrate from SubProgressMonitor to SubMonitor

[vogella]

Migrated all usages of the deprecated SubProgressMonitor class to use SubMonitor following Eclipse 4.6+ best practices:

• resources/Policy.java: Updated subMonitorFor() to use SubMonitor.convert()
• team/InfiniteSubProgressMonitor: Refactored from inheritance to composition, now implements IProgressMonitor and delegates to SubMonitor
• team/SubscriberSyncInfoEventHandler: Replaced anonymous SubProgressMonitor with IProgressMonitor wrapper that delegates to SubMonitor

All changes follow the official Eclipse SubMonitor migration guide.

[github-actions[bot]]

Test Results

 1 872 files   -  81   1 872 suites   - 81   1h 16m 28s ⏱️ - 7m 12s  4 591 tests  - 153   3 879 ✅  -   841   24 💤 ± 0    686 ❌ +  686  2 🔥 +2  13 773 runs   - 459  11 848 ✅  - 2 202  165 💤  - 17  1 756 ❌ +1 756  4 🔥 +4 

For more details on these failures and errors, see this check.

Results for commit 50398d1f. ± Comparison against base commit 3e8e40e7.

This pull request removes 153 tests.

AllCompareTests AsyncExecTests ‑ testCancelOnRequeue
AllCompareTests AsyncExecTests ‑ testQueueAdd
AllCompareTests AsyncExecTests ‑ testWorker
AllCompareTests CompareFileRevisionEditorInputTest ‑ testPrepareCompareInputWithNonLocalResourceTypedElements
AllCompareTests CompareUIPluginTest ‑ testFindContentViewerDescriptorForTextType_StreamAccessor
AllCompareTests CompareUIPluginTest ‑ testFindContentViewerDescriptor_TextType_NotStreamAccessor
AllCompareTests CompareUIPluginTest ‑ testFindContentViewerDescriptor_UnknownType
AllCompareTests ContentMergeViewerTest ‑ testFFFX
AllCompareTests ContentMergeViewerTest ‑ testFFTX
AllCompareTests ContentMergeViewerTest ‑ testFFXF
…

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