remove (ice-9 debugger) and (ice-9 debugging)

remove (ice-9 debugger) and (ice-9 debugging)

* module/ice-9/debugger.scm:
* module/ice-9/debugger/command-loop.scm:
* module/ice-9/debugger/commands.scm:
* module/ice-9/debugger/state.scm:
* module/ice-9/debugger/trc.scm:
* module/ice-9/debugger/utils.scm:
* module/ice-9/debugging/breakpoints.scm:
* module/ice-9/debugging/example-fns.scm:
* module/ice-9/debugging/ice-9-debugger-extensions.scm:
* module/ice-9/debugging/load-hooks.scm:
* module/ice-9/debugging/steps.scm:
* module/ice-9/debugging/trace.scm:
* module/ice-9/debugging/traps.scm:
* module/ice-9/debugging/trc.scm: Remove these files, as we will favor
  the REPL's implementation of a debugger, and (system vm traps) and
  (system vm trap-state). But these old files will continue to inspire
  the rest of the new debugger interface.