Readded mergeDST.py after modernization, and added testing

Closes #380 (closed) Goes with lhcb-datapkg/PRConfig!514 (merged)

/ci-test

requested review from @cburr

added ci-test-triggered label

added RTA label

• [2025-02-10 08:13] Validation started with lhcb-master-mr#12527
• [2025-02-10 10:06] Validation started with lhcb-master-mr#12530
• [2025-03-18 15:25] Validation started with lhcb-master-mr#12922
• [2025-03-18 17:30] Validation started with lhcb-master-mr#12928
• [2025-03-19 10:27] Validation started with lhcb-master-mr#12942
• [2025-03-24 09:13] Validation started with lhcb-master-mr#13033
• [2025-03-24 10:54] Validation started with lhcb-master-mr#13038
• [2025-03-24 11:39] Validation started with lhcb-master-mr#13043

resolved all threads

/ci-test --without-downstream lhcb-datapkg/PRConfig!514 (merged)

changed the description

added 1 commit

• 4c9ba2fc - Apply 1 suggestion(s) to 1 file(s)

Compare with previous version

mentioned in issue Moore#910 (closed)

mentioned in merge request !4857 (closed)

mentioned in issue Moore#915 (closed)

added 43 commits

• 4c9ba2fc...a24d3db6 - 37 commits from branch master
• 0f3ba633 - Revert "Dropped unused option file mergeDST.py"
• 9befe0f5 - Replaced usage of root_copy_input_writer
• ed903a74 - Added test for mergeDST
• b352f95f - Apply 1 suggestion(s) to 1 file(s)
• f2ba8bc2 - Improve test_mergedst tests
• 3d1a9c8a - Fix using write_options_to_fsr with compression options

Compare with previous version

mentioned in issue Moore#927 (closed)

mentioned in issue Moore#936

added 46 commits

• 3d1a9c8a...0b0dc4bc - 41 commits from branch master
• d91dd3b6 - Fixed lbexec options for pydantic 2
• 84cc62a6 - Dropped unused code in components.py
• 9e69ac9f - Improved and simplified configure method in application.py, also allowing to reuse only part of it
• bfb96eeb - Fix using write_options_to_fsr with compression options
• 14305fb4 - Recreated mergeDST.py using PyConf

Compare with previous version

resolved all threads

/ci-test --without-downstream lhcb-datapkg/PRConfig!514 (merged)