feat: add Yamato settings and a test project (#31)

[sindharta]

• Add initial Yamato settings
• Add empty project for testing the package directly
• Modify gitignore to ignore test project's temp files
• Add npmignore to omit package-unrelated files from being added to the package
• Add a dummy package.json in the test project.
• Create symbolic links in the test project, so that it refers to the actual package
• Ignore autogenerated Visual Studio files
• Add missing meta files
• Create a symbolic link to Tests
• Removing sample tests
• Fixed Failed LastImport test. Removed Experimental PrefabBuilder Tests.
• Commenting out LastImportedItemsTest.TestLastImportedItems