[RF] Rename stuff in RooMomentMorph(Func)ND to ease spotting difference

[guitargeek]

In order to merge the RooMomentMorphND and the RooMomentMorphFuncND, it is better to rename things first such that the code becomes comparable. Like this, it will be easier to spot the residual differences.

[phsft-bot]

Starting build on ROOT-debian10-i386/soversion, ROOT-performance-centos8-multicore/cxx17, ROOT-ubuntu18.04/nortcxxmod, ROOT-ubuntu2004/python3, mac12/noimt, mac11/cxx14, windows10/cxx14
How to customize builds

[phsft-bot]

Build failed on mac12/noimt.
Running on macphsft17.dyndns.cern.ch:/Users/sftnight/build/jenkins/workspace/root-pullrequests-build
See console output.

Warnings:

• [2023-01-10T17:39:17.386Z] /Users/sftnight/build/jenkins/workspace/root-pullrequests-build/root/core/base/src/TDirectory.cxx:1245:7: warning: 'sprintf' is deprecated: This function is provided for compatibility reasons only. Due to security concerns inherent in the design of sprintf(3), it is highly recommended that you use snprintf(3) instead. [-Wdeprecated-declarations]

Failing tests:

• projectroot.roottest.cling.const.roottest_cling_const_run2
• projectroot.roottest.cling.dict.roottest_cling_dict_rundefaultargs_compiled
• projectroot.roottest.cling.dict.roottest_cling_dict_exectemplatetemplateTest
• projectroot.roottest.cling.dict.roottest_cling_dict_runalgebra
• projectroot.roottest.cling.functionTemplate.roottest_cling_functionTemplate_testcint
• projectroot.roottest.cling.other.roottest_cling_other_runsprintfselect
• projectroot.roottest.cling.parsing.roottest_cling_parsing_ptrconst
• projectroot.roottest.cling.printf.roottest_cling_printf_star
• projectroot.roottest.cling.template.roottest_cling_template_defaultTemplateParam
• projectroot.roottest.cling.typedef.roottest_cling_typedef_assertFuncArray

And 63 more

[phsft-bot]

Starting build on ROOT-debian10-i386/soversion, ROOT-performance-centos8-multicore/cxx17, ROOT-ubuntu18.04/nortcxxmod, ROOT-ubuntu2004/python3, mac12/noimt, mac11/cxx14, windows10/cxx14
How to customize builds

[phsft-bot]

Build failed on ROOT-ubuntu2004/python3.
Running on root-ubuntu-2004-3.cern.ch:/home/sftnight/build/workspace/root-pullrequests-build
See console output.

Failing tests:

• projectroot.roofit.multiprocess.test.gtest_roofit_multiprocess_test_test_RooFit_MultiProcess_ProcessTimer

[lmoneta]

I don't understand why you need to rename the internal class Grid -> Grid2 ?
This might causes I/O problem in case the class is streamed.

Otherwise the PR looks fine to me

[guitargeek]

That's exactly the right observation! In fact the ClassDef and LinkDef entry for RooMomentMorphND::Grid is missing, so users could not do IO with it.

Therefore, we have the nice opportunity to make the RooMomentMorphND consistent with the RooMomentMorphFuncND (for which the Grid2 LinkDef entry exists) without breaking backwards compatibility. And if we see that these classes are just the same besides using a different base class, we can even remove RooMomentMorphND and tell users to use RooMomentMorphFuncND with the RooPdfWrapper adapter, like we do for many other classes.

[lmoneta]

OK, thanks for the clarification!