Modularized SimpleShaderInspector class

[Cibbi]

This pr aims to separate behaviours currently happening inside the SimpleShaderInspector class.

In particular a lot of functions that are not required to be inside the SimpleShaderInspector class have been moved away, mainly to the SSIHelper class.

This makes possible to introduce a ISimpleShaderInspector interface that can be used whenever a user wants to make its own inspector without relying on the provided base class, but still having the ability to use single functions that were previously contained inside the SimpleShaderInspector class. Controls are now also able to access a ISimpleShaderInspector property that should contain the inspector they are displayed on, granted the inspector implementation takes care of setting that property in its controls during initialization.

This also needed a small rework of the localization system in order to make people able to use it in their own inspector implementations.

[Cibbi]

From some quick tests, these changes also improved inspector initialization time by around 30%, probably due to changes to the localization loading being less convoluted.