[Move objects] Expose structured representation of a disassembled package

[sblackshear]

Today, the explorer shows a string representation of a disassembled Move package. This is very cool, but it would be even niftier if we could show a structured representation of the package that links to types and functions used elsewhere. To support this, we need to do the following:

Use a normalized::Module instead of a string representation of the disassembled module here and ensure that it gets turned into nicely structured JSON that the explorer can understand