Solution conversion 5.7.0

• Update to .NET Standard 2.0
• Convert solution and project files
• Added convert and copy to clipboard into options

VB -> C#

• Convert WithEvents/Handles
• Convert Handles and WithEvents similarly to the VB compiler
• Handle expressions in Select Case
• Ensure all parts of a partial class have the partial modifier
• Handle missing optional arguments
• Increase number of default global imports for web conversion
• Default properties now converted

C# -> VB

• Fix DeclarationExpressions without a type throwing exception
• Convert Throw Expressions to multi-line lambda function
• Convert properties with no accessors
• Fix error converting ObjectCollectionInitializerSyntax within object initializer
• Escape predefined if they are used for the name of declaration