Additional find/exclude/plot options for nested properties

[nblumhardt]

Raised by @TysonMN at datalust/serilog-sinks-seq#141

(Considering a nested ExceptionDetail property created by Serilog.Exceptions) ... I can interact with each sub-property. However, the available options are not the same as a top-level property. Also, I dislike still seeing the characters that are define the JSON syntax (namely curly braces at the beginning and end, colons between keys and values, single quotes arounds values, and commas after values).

I was hoping that Seq would display the data more like this ... where all the checks have the same options, all the Xs have the same options, and the triangle next to ExceptionDetail toggles between the view in that image and all those sub-properties inlined to the right of ExceptionDetail (and the triangle points to the right when the sub-properties are inlined).