Cleanup deprecated code

[uhafner]

Supersedes #327

[github-actions]

☀️   Quality Monitor

   🚦   Tests: 98% successful (✔️ 299 passed, 🙈 7 skipped)
   〰️   Line Coverage: 76% (714 missed lines)
   ➰   Branch Coverage: 67% (278 missed branches)
     CheckStyle: No warnings
     PMD: No warnings
     SpotBugs: No bugs
   🌀   Cyclomatic Complexity: 820 (total)
   💭   Cognitive Complexity: 530 (total)
   📏   Lines of Code: 9835 (total)
   📝   Non Commenting Source Statements: 3547 (total)
   🔭   Access to foreign data: 513 (total)
   🔗   Class cohesion: 100.00% (maximum)
   📤   Fan out: 1315 (total)
   📲   Number of accessors: 122 (total)
   ⚖️   Weight of a class: 100.00% (maximum)
   📐   Weighted method count: 1045 (total)
   ➿   N-Path Complexity: 1428 (total)

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Created by Quality Monitor v1.14.0 (#f3859fd). More details are shown in the GitHub Checks Result.