Visual Shader: Add vector operations to Remap node

[tetrapod00]

Implements and closes godotengine/godot-proposals#10800.

Add vector operators to the Remap node, following the example of the Mix node.

Remap operators after this PR:

Remap ranges can be set with either scalars or vectors:

Move existing default scalar Remap to the scalar functions section.

Implementation:

• Follow the example of Mix for the operator types.
• Copy the operator code from Mix.
• Add Remap to VisualShaderEditor::_setup_node(), so that it can be added with either float or vector values.
• The old scalar mode is still the default, so backward compatibility should work. I don't think changing the category should break anything?

[tetrapod00]

Corrected an error where OP_TYPE_VECTOR_2D_SCALAR, OP_TYPE_VECTOR_3D_SCALAR, and OP_TYPE_VECTOR_4D_SCALAR were mixing float and vector values in the remap calculation.

[akien-mga]

Thanks!