Is your feature request related to a problem? Please describe.
I'm currently trying to write a script for exporting the PCode representation of a program
for use in a different project of mine. While writing the script, I noticed that basic blocks
representing switch-case blocks do not contain information describing which outgoing basic block
corresponds to which switch-case label.

Depending on what proposal is more favorable, I can also work on a pull request implementing
the feature.

Describe the solution you'd like
Proposal 1.)
Expose the default case address in JumpTable for the corresponding switch-case block. This can be
either done by defining a new field (like Address defaultCase = null;) in the class or adding a
case address to the cases field, specifying that the last entry always corresponds to the default case.

Proposal 2.)
Expose the default case through the label field in BlockEdge. Right now, the field seems to be unused
even though in the decompiler the field gets populated (and also has a flag marking the default switch case).

Describe alternatives you've considered
See above.

Additional context

code from Ghidra/Features/Decompiler/src/decompile/cpp/block.cc: label is populated but does not get encoded.