Add configuration file support for Nuget feeds and packages

[mikoskinen]

Currently configuration file supports the configuration of Assembly and Folder catalogs.

Add support for configuring feed and package catalogs.

[mikoskinen]

Currently the IConfiguration support is provided using the following two classes:

FolderCatalogConfigurationConverter
AssemblyCatalogConfigurationCoverter

When implementing this feature we should add one for nuget feeds and one for nuget packages. These should be added into Weikio.PluginFramework.Catalogs.Nuget.

The converters must be registered into the DI before they can be used:

        services.AddTransient(typeof(IConfigurationToCatalogConverter), typeof(NugetFeedCatalogConfigurationConverter));
        services.AddTransient(typeof(IConfigurationToCatalogConverter), typeof(NugetPackageCatalogConfigurationCoverter));