Watch expression on value opened in new window

[zspitz]

When opening the value of an expression node in a new window, the WatchExpressionFormatString for the root ExpressionNodeData needs to be updated to the parent root.

[zspitz]

We can either recreate the watch expression in the ResolvePath function, or we can pass it along when setting the Path.

[zspitz]

Two functions:

1. generate cast + access from a single path component
2. generate cast and access from a full path

Part of the second function would be to handle values:

• if the object is a ConstantExpression then use the Value property and cast to the narrowest public type of the object at the Value property
• if the object is a closed-over variable MemberAccessExpression then copy the logic from ExtractValue -- wrap in a call to Lambda, Compile and Invoke

[zspitz]

If the debugged expression has been set in the source window, pass it along with the options.