Plugin for converting from [VisualShader] to [Shader]. [VisualShaderConversionPlugin] is invoked when the context menu is brought up for a [VisualShader] in the editor inspector. Takes an input [Resource] expected to be of type [VisualShader] and converts it to [Shader] in [method converts_to]. The returned [Resource] is the resulting [Shader] of the conversion, and the input [Resource] remains unchanged. Returns "Shader" which is the class name [Shader] this plugin converts the source resource [VisualShader] to. Called to determine whether a particular [Resource] can be converted to the [Shader] resource type by this plugin. Will return false if the particular [Resource] is not of type [VisualShader].