Minor services improvement and extending features set

[Vasar007]

Changes list:

• Refactored magic strings;
• Added dummy top list editor page;
• Created view model for toplist editor view;
• Refactored desktop and config options.
• Refactored contract and options;
• Removed any CPU configuration from solution;
• Simplified view model names;
• Added default values for settings varibables that can be read from system environment variables;
• Added new views and view models for toplist editor;
• Added default values for environment variables;
• Updated NuGet packages;
• Removed old style package.config;
• Removed extra links to packages in some projects;
• Added user control for toplist item;
• Extended utilities extensions methods class;
• Fixed typos and style error in doc strings;
• Specified proper type for null string case;
• Simplified Thing class model;
• Added additional observable collections;
• Renamed ResponseMetaData -> ResponseMetadata;
• Updated some packages;
• Implemented logic to work with toplist items;
• Unified XAML style in views;
• Placed private static methods after public isntance methods;
• Removed button triggers (may be return later);
• Renamed project DTO -> Models;
• Refactored RelayCommand;
• Improved UI and fixed some UI bugs;
• Extended IEnumerable extensions;
• Added serializable attribute to models;
• Specified build platfrom for desktop app;
• Created dummy credentials.json for CI;
• Fixed typo in README;
• Unified namespaces by code convention;
• Fixed incorrect check for TMDB config image value;
• Added ILogger interface to provide more flexible way to work with logging later;
• Improved log messages and make it easier to read;
• Added new layouts for NLog;
• Added header and footer messages;
• Changed logging mode to async;
• Added newlines for footer and header in logging;
• Added option to control newline replacement in exception messages for logging;
• Added PrintFooter methods fot ILogger;
• Added "sealed" qualifier for all classes where it is not required that class could be used as base;
• Changed acess level for method and specify call to base static method with same name
• Renamed folder: Library -> Libraries;
• Removed extra calls to logger for exceptional cases;
• Updated NuGet packages;
• Created projects for external services to avoid code mash.
• Added adapters for external libs;
• Simplified Dispose method for all disposable classes;
• Added exception handling for external dependencies in adapters;
• Changed own string equals method to standard call.

Closing issues

Close #41;
Close #42;
Close #43;
Close #44.