Calculated columns improvements

[dbarashev]

• Calculated default columns (end date and cost) are not calculated anymore.
• Less custom property change events when loading a project.

Update #2514

[github-actions]

Test Results

315 tests  +2   315 ✅ +2   23s ⏱️ ±0s
 83 suites ±0     0 💤 ±0 
 83 files   ±0     0 ❌ ±0 

Results for commit 99cb16d. ± Comparison against base commit f94a68b.

This pull request removes 1 and adds 3 tests. Note that renamed tests count towards both.

net.sourceforge.ganttproject.customProperty.CustomPropertyImportTest ‑ testImportDuplicatedProperties

net.sourceforge.ganttproject.customProperty.CustomPropertyImportTest ‑ import preserves property id()
net.sourceforge.ganttproject.customProperty.CustomPropertyImportTest ‑ import triggers only one event()
net.sourceforge.ganttproject.customProperty.CustomPropertyImportTest ‑ testImportDuplicatedProperties()

♻️ This comment has been updated with latest results.