Material editor shader settings & features not updated after compilation

[adriengivry]

Description
The material editor currently generate widgets for shader uniforms and features when a material is selected, or its associated shader updated. Compiling a shader doesn't trigger the material editor to update its widgets.

To Reproduce
Steps to reproduce the behavior:

1. Open a material in the material editor
2. Add a feature to the shader used by this material (example: add #feature FOO somewhere in the shader code)
3. Compile the shader from its contextual menu in the asset browser
4. Notice that the material editor isn't updated to show this new feature

Expected behavior
The material editor should always be updated after a shader has been compiled.

Screenshots
N/A

[adriengivry]

Partially fixed by #587

Compiling a material's shader using the new material editor "Compile Shader" button will also make sure the properties and features are up-to-date.

Using the asset browser's "Compile" action on a shader still won't.