clean up RNTuple and add precompile

[Moelf]

julia> using UnROOT

# this PR
julia> @time @eval LazyTree("./test/samples/RNTuple/test_ntuple_stl_containers.root", "ntuple");
  2.566458 seconds (1.20 M allocations: 81.511 MiB, 1.13% gc time, 99.86% compilation time)

# main
julia> @time @eval LazyTree("./test/samples/RNTuple/test_ntuple_stl_containers.root", "ntuple");
  3.751967 seconds (3.19 M allocations: 214.859 MiB, 0.50% gc time, 99.87% compilation time)

# this PR
julia> @time @eval ROOTFile("./test/samples/RNTuple/test_ntuple_stl_containers.root")["ntuple"];
  0.050435 seconds (9.07 k allocations: 623.125 KiB, 96.67% compilation time)

# main
julia> @time @eval ROOTFile("./test/samples/RNTuple/test_ntuple_stl_containers.root")["ntuple"];
  1.177235 seconds (2.00 M allocations: 134.056 MiB, 1.69% gc time, 99.79% compilation time)

[codecov[bot]]

Codecov Report

Attention: 1 lines in your changes are missing coverage. Please review.

Comparison is base (785b453) 86.34% compared to head (f4a1146) 86.32%.

Files	Patch %	Lines
src/RNTuple/footer.jl	93.33%	1 Missing :warning:

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #303 +/- ## ========================================== - Coverage 86.34% 86.32% -0.02% ========================================== Files 18 18 Lines 2438 2443 +5 ========================================== + Hits 2105 2109 +4 - Misses 333 334 +1 ```

:umbrella: View full report in Codecov by Sentry.
:loudspeaker: Have feedback on the report? Share it here.