Facilitate creation of Model from Python bindings

[S-Dafarra]

This PR does the following:

• add some setter methods to ease the setting of the model visual solid shapes from the bindings
• removed the use of double& when setting the limits and the friction of a joint, as the values were effectively copied
• bumped the version (as the API has changed)
• removed some whitespace and included Visual Studio files in the gitignore

[traversaro]

Thanks! I will bump the major version as for iDynTree I do the exercise of keeping ABI compatibility in major versions (mainly to simplify conda packaging). Other then that it seems great, thanks. cc @francesco-romano any opinion on this? I guess this should not interfere with the pybind11 bindings, but anyhow you may want to have a look.

[francesco-romano]

Yes it should not change anything on PyBind11.

Good changes. At some point you should start thinking about removing those new and delete and start using unique_ptr. iDynTree would benefit a lot from that