improved shdr_data module

[ScanMountGoat]

There are a few goals for this module. This should cover the necessary functionality for https://github.com/ScanMountGoat/Smush-Material-Research. Perfectly rebuilding the shader binaries is not a goal at this time. The large amount of header and footer information makes it unrealistic to research all of it.

• export nushdb metadata for uniforms, buffers, etc from the footer for use with decompiled shaders
• extract the program binary code itself for each shader

[ScanMountGoat]

The easiest is probably to create functions that take a Shdr from ssbh_lib as input and return some data. The returned data could be higher level or lower level representations of the binary data depending on the use case. Creating conversion APIs similar to the other ssbh_data types won't work well due to all the missing fields. This module is a niche use case, so the API likely won't be very stable over time.