[ntuple] add different modes of descriptor loading to RNTupleSerializer #15659

Job	Run time
Upload Event Payload	3s
Windows 10 x64 Release	1h 2m 28s
Windows 10 x86 Release	1h 50m 49s
mac13 ARM64 LLVM_ENABLE_ASSERTIONS=On, builtin_zlib=ON	50m 7s
fedora40 LLVM_ENABLE_ASSERTIONS=On, CMAKE_CXX_STANDARD=20	1h 18m 13s
mac14 X64 LLVM_ENABLE_ASSERTIONS=On, CMAKE_CXX_STANDARD=20	1h 17m 44s
fedora41 LLVM_ENABLE_ASSERTIONS=On	49m 35s
mac15 ARM64 LLVM_ENABLE_ASSERTIONS=On, CMAKE_CXX_STANDARD=20	40m 21s
alma8 LLVM_ENABLE_ASSERTIONS=On	1h 29m 5s
mac-beta ARM64 LLVM_ENABLE_ASSERTIONS=On, CMAKE_CXX_STANDARD=20	43m 44s
alma9 LLVM_ENABLE_ASSERTIONS=On, CMAKE_BUILD_TYPE=Debug	1h 57m 3s
ubuntu22 imt=Off, LLVM_ENABLE_ASSERTIONS=On, CMAKE_BUILD_TYPE=Debug	2h 20m 50s
ubuntu2404 LLVM_ENABLE_ASSERTIONS=On, CMAKE_BUILD_TYPE=Debug	2h 33m 20s
ubuntu2410 LLVM_ENABLE_ASSERTIONS=On, CMAKE_BUILD_TYPE=Debug	2h 27m 29s
debian125 LLVM_ENABLE_ASSERTIONS=On, CMAKE_CXX_STANDARD=20	1h 8m 59s
alma9 modules_off runtime_cxxmodules=Off	1h 11m 43s
alma9 march_native CMAKE_BUILD_TYPE=RelWithDebInfo, CMAKE_CXX_FLAGS=-march=native, CMAKE_C_FLAGS=-march=native, fortran=OFF	1h 7m 36s
alma9 arm64 CMAKE_BUILD_TYPE=RelWithDebInfo	55m 11s
alma9-clang clang LLVM_ENABLE_ASSERTIONS=On, CMAKE_C_COMPILER=clang, CMAKE_CXX_COMPILER=clang++	1h 18m 35s
	1d 1h 2m 55s

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