Expand shader viewer for really long source. Closes #57
Add support for arrays in the buffer viewer. Closes #56

For now this just acts like a really wide vector with N columns for the
array, but this could be improved in future if a better visualisation is
decided on.
Fix shader debugging always reading from pixel resources. Closes #59

Instead of assuming that we can sample straight from the bound resource,
we save what's bound on PS slot 0, always sample from that slot, and
bind whatever resource & sampler onto PS slot 0 for the sampling draw.