[REQ] Support writing to textures

[nvlukasz]

Description

Use surf**read() and surf**write() in kernels if surface access is enabled for textures.

Example:

@wp.kernel
def brighten(tex: Texture2D, gamma: float):
   x, y = wp.tid()
    u = (wp.float(x) + 0.5) / wp.float(width)
    v = (wp.float(y) + 0.5) / wp.float(height)

    value = wp.surface_read(tex, u, v)
    value = wp.pow(value, gamma)
    wp.surface_write(tex, u, v, value)

Context

This could be useful in sensor processing pipelines, DLSS, etc.