Add cmake function to handle plugin meta data

[alxvth]

Add a CMake helper function that handles plugin meta data from a ./PluginConfig.json file.

• Appends the plugin version to the output file name
• For Visual Studio, set up the target in the plugin type folder (optional)

Example ./PluginConfig.json, see ManiVaultStudio/Scatterplot#176:

{
    "name" : "Scatterplot View",
    "version" :  {
        "plugin" : "1.0.0",
        "core" : ["1.3"]
    },
    "type" : "Viewer",
    "dependencies" : ["Points"]
}

The fields name, version::plugin are required for the new mv_handle_plugin_config helper function. type is optional. dependencies is used in the core IIRC. version::core is so far unused but informative and might be used in the future.

[alxvth]

It works with both DevBundle and stand-alone (find_package)