Cleanup/rename etc. dashed line shaders.

Goal is to make them more modular, to allow more variants (variable
single-color, thickness, ...) to be added without having to
copy-and-change-one-line of whole chain of shaders.

source/blender/editors/transform/transform_constraints.c

@@ -735,7 +735,7 @@ void drawConstraint(TransInfo *t)
 
 			const uint shdr_pos = GWN_vertformat_attr_add(immVertexFormat(), "pos", GWN_COMP_F32, 3, GWN_FETCH_FLOAT);
 
-			immBindBuiltinProgram(GPU_SHADER_3D_LINE_DASHED_COLOR);
+			immBindBuiltinProgram(GPU_SHADER_3D_LINE_DASHED_UNIFORM_COLOR);
 
 			float viewport_size[4];
 			glGetFloatv(GL_VIEWPORT, viewport_size);