[SofaKernel] change data content copy on write condition

[damienmarchal]

The Data's hold their actual content within a dedicated container called DataContentValue.
Two versions of this containers exists, on holding the data using a copy-on-write mechanism while an other is using a systematic copy.

Currently the selection is based on the content of DataTypeInfo, I found it more explicit and clear to rely on type_traits to select the proper DataContentValue version.

Caduceuse, 10 000 iterations:
  - master: 24.15 s
  - copy on write to true: 24.2 s
  - copy on write to false: 23.78 s
  - copy on write to is_scalar: 25.0 s
  - copy on write to !is_scalar: 23.0 s

collisionMultiple.scn, 1 000 iterations:
  - master: 15.9 s
  - copy on write to true: 15.9 s
  - copy on write to false: 14.7 s
  - copy on write to is_scalar: 16.3 s
  - copy on write to !is_scalar: 14.5 s
  
 beam16x16x76-hexafem-rk4-CPU.scn: 2000 iterations
  - master: 1 m 30
  - copy on write to true: 1 m 32
  - copy on write to false: 1 m 30 
  - copy on write to is_scalar:  1 m 26
  - copy on write to !is_scalar: 1 m 18
  
  TorusFall: 4000 iterations
  - master: 41.5 s
  - copy on write to true: 43.9 s
  - copy on write to false: 41.2 s 
  - copy on write to is_scalar: 43.3 s  
  - copy on write to !is_scalar: 42.5 s

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• it builds with SUCCESS for all platforms on the CI.
• it does not generate new warnings.
• it does not generate new unit test failures.
• it does not generate new scene test failures.
• it does not break API compatibility.
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[hugtalbot]

what test should be performed to check the performance impact @damienmarchal ?

[damienmarchal]

I just added the performances tests... not very significant on "classical" scenes. So for the moment I suggest keeping the two version of DataContentValue<> but merge de PR to remove the dependency to DataTypeInfo.

[damienmarchal]

[ci-build]