[Code Review] Remove the usage of "partial" and other coding style issues.

[jasonkuo41]

partial keyword is meant to be used when compiling to different target framework, platform, and configuration and is not to be abused like it is in this project.

Also, keep each class per file. Although it's sometimes acceptable to do so given certain reasons as long as they are consistent, in this project is doesn't seem like it.

Nested class should either be at the front, or at the end of the class and shouldn't be placed at anywhere else and should be consistent across the project.

Naming conventions are also not consistent. Some classes are camelCases while most are PascalCases. Microsoft and I both recommend using PascalCase across the board.