Look for matching Conan profile in a config file for the running VS configuration

[jgsogo]

The extension looks into a file conan.config.json for a Conan profile name associated with the Visual Studio configuration. This file is searched first in the same directory as the VS Project, and then in any parent directory.

The format for this file (it should be extensible in the future):

{  
   "configurations": {  
      "Release|Win32": "release_win32",
      "Debug|x64": "debug_x64",
      "Release|Win64": "C:/conan/profiles/release_win64"
   }
}

Under the "configurations" key there is a dictionary with the correspondence between the VS configuration (key, on the left) and a Conan profile (value, on the right). To take into account:

• VS creates the configuration name joining with a | character the name of the Configuration and the Platform.
  
• For Conan profiles, the value declared will be used verbatim for the --profile argument in the conan install command, and rules related to profile lookup applies.

closes #88
related to #5 (first iteration)

[jgsogo]

Please, @SSE4 , review again and test the functionality. I think it could be almost ready. 😸

[SSE4]

I think it deserves an example project with:

1. custom configuration names
2. json config file
3. profiles for it

[jgsogo]

Very basic example added, check it works as expected (using the visual_studio generator #108). Thanks

[SSE4]

works for me, please un-draft the PR