Fix the following compilation error on Windows:
```
testHistFactory.obj : error LNK2019: unresolved external symbol "class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> > const & __cdecl RooFit::tmpPath(void)" (?tmpPath@RooFit@@YAAEBV?$basic_string@DU?$char_traits@D@std@@v$allocator@D@2@@std@@xz) referenced in function "public: virtual void __cdecl HFFixture_ModelProperties_Test::TestBody(void)" (?TestBody@HFFixture_ModelProperties_Test@@UEAAXXZ)
testHistFactory.exe : fatal error LNK1120: 1 unresolved externals
```

The first implementation of RooFitH3 had a number of shortcomings, which this
PR addresses.

In detail:

  * It is now possible to read JSON files independent of the ordering
  * A priority mechanism has been implemented for importers and exporters
  * Duplicate and dead code has been removed
  * Many small bugs have been fixed
  * The JSONInterface has been made public and moved from Detail to
    Experimental, so users can write their own importers & exporters
  * The two unit tests have been fixed

Co-authored-by: Nicolas Morange <nicolas.morange@cern.ch>
Co-authored-by: Jonas Rembser <jonas.rembser@cern.ch>

The usecase for this overload is to transfer the ownership of RooAbsArgs
from `std::unique_ptr` to another RooAbsArg, without having to call
`release()` on the smart pointer, which is a code smell because
ownership should always be clear without the smart pointer having to
release it.

Calling `new` and `delete` is now completely avoided in RooFitHS3, and
`std::unique_ptr` is always used instead.

Unlike instance methods, a `property` object in Python 2 has no
`__func__` attribute and can be reassigned to a new class directly.

  * Add two tutorials `rf711_lagrangianmorph` and `rf712_lagrangianmorphfit` to
    demonstrate the usage of the `RooLagrangianMorphFunc` class

  * The commit also includes an update to `rf512_wsfactory_oper` showing an
    example for the new options of `taylorexpand` and `lagrangianmorph`

  * formatting of `tutorials/roofit/rf710_roopoly.py`

  * The attribute for new physics couplings in the `RooLagrangianMorphFunc`
    class is changed from `NP` to `NewPhysics` to avoid confusion with other
    abbreviations

  * The `lagrangianmorph` factory interface is update to accept arguments in
    any order

This is presumbaly a bit controversial.

safeDeleteList remove elements in order in a RooAbsCollection,
starting with the ones that only have clients and no servers.

This is a slow process, and takes 25% of CPU time on large workspace
manipulation workflows, as it takes place at each workspace::import
call. It can also lead to slow ~RooWorkspace.

The point is, I don't think this logic is needed at all.
~RooAbsArg takes care of properly breaking all the client-server links,
both uplinks and downlinks, for every object. I couldn't find a logical
case where a crash would occur if the safeDeleteList logic were to be
removed.

All RooFit tests pass after this patch. No problem for my heavy
workspace manipulation worflows either.

[RF] Include RooAbsData objects in the RooNameReg

The logic from RooAbsArg is copied into RooAbsData.

This allows to use the hash-map functionality of RooLinkedList
for RooAbsData objects, as the namePtr mechanism allows to track
renaming and therefore avoids false negatives that result in
linear scans of the collection.

In turn, this improves significantly the run-time of large workspace
imports (x2 to x4), which were dominated by embeddedData() calls.
This patch is based on the JSON tool use-case, but presumably will
significantly also improve other heavy uses of workspace import, such
as Higgs combination workspaces manipulation workflows.

The cost of one additional pointer per RooAbsData object seems a low
price to pay.