Interrupting Normaliz crashes M2

Normaliz is used by the engine for computing the Fourier-Motzkin algorithm and finding Hilbert bases, but on larger examples interrupting it seems to crash M2 ungracefully:
```m2
ii82 : Hom(sheaf L#0, sheaf L#1)
C-c C-cterminate called after throwing an instance of 'libnormaliz::InterruptException'
what(): Interrupted: external interrupt
Error, user interrupt
/bin/sh: line 1: 28184 Aborted (core dumped) ~/M2/M2/BUILD/build/M2 --no-readline --print-width 126

Process M2 exited abnormally with code 134
```

Reproduce the interruption using the Hom(sheaf L#0, sheaf L#1) example and observe Normaliz while it computes Fourier-Motzkin data or Hilbert bases. Trace how the libnormaliz::InterruptException reaches the M2 engine; done means interrupting the computation exits gracefully without an abort or core dump.

Written by the indexing model from the issue text.