gpu: add debug tags to pl_tex/pl_buf

Intended to make error messages even more easily traceable, by tagging all created GPU resources with a debug tag clearly indicating where in the source that resource came from.

Thanks to the new API style of using defines to set default properties, this is largely transparent to automate adding.

As an aside, also fix a shortcoming of the pl_vulkan_wrap API where it currently did not support forwarding user_data.