feat: Customize ImageShader properties

[Zfinix]

Description

Currently, there is no way to set the properties of samplerUniforms so if you define a sample e.g.

uniform sampler2D iChannel0;

In the generated dart you get:

  return program.shader(
      floatUniforms: Float32List.fromList(...),
      samplerUniforms: [
        ImageShader(
          iChannel0,
          TileMode.repeated,
          TileMode.repeated,
          UmbraShader.identity,
        ),
      ],
    );

Requirements
I want to be able to define ImageShader's TileMode tmx, TileMode tmy and Float64List matrix4, values without having it revert back to default values each time I generate shaders.