Calling destroy() on an inspector instance should remove the inspector-json class

[localjo]

Initiating Inspector-JSON on an element adds an inspector-json class to that element, which is used for CSS styling, among other things. When destroy() is called, that class remains, and causes potential CSS conflicts. The class should probably be removed when the inspector is destroyed.

[localjo]

This is related to solidusjs/devtools-solidus#2