[VisualShader] Add w output to TransformVectorMult, improve dropdown entries

[QbieShay]

Describe the project you are working on

godot

Describe the problem or limitation you are having in your project

#8375

Additionally, the dropdown menu is really non intuitive for people that aren't already familiar with matrix multiplication.
Since visual shader is a tool that's suited for both technical and less technical people, the names there should be more human-readable than math-correct.

Describe the feature / enhancement and how it helps to overcome the problem or limitation

Allow reading the w output of the transformation, so that one can perform depth linearization.
Change the dropdown names from:

• TransformPoint(AxB)
• TransformPoint(BxA)
• TransformDirection(AxB)
• TransformDirection(BxA)

Describe how your proposal will work, with code, pseudo-code, mock-ups, and/or diagrams

If this enhancement will not be used often, can it be worked around with a few lines of script?

Is there a reason why this should be core and not an add-on in the asset library?