Add SnapshotModule to qemu_launcher

[WorksButNotTested]

I've put this together, but it seems to crash after a while when run with...

/workspaces/LibAFL/fuzzers/binary_only/qemu_launcher/target/x86_64/release/qemu_launcher-x86_64 \
  --input ./corpus \
  --output /workspaces/LibAFL/fuzzers/binary_only/qemu_launcher/target/x86_64/output/ \
  --log /workspaces/LibAFL/fuzzers/binary_only/qemu_launcher/target/x86_64/output/log.txt \
  --cores 0-4 \
  --snapshots \
  --iterations 1000 \
  --verbose \
  -- \
  /workspaces/LibAFL/fuzzers/binary_only/qemu_launcher/target/x86_64/libpng-harness-x86_64

[domenukk]

Clippy is still complaining

warning: unused import: `libafl_qemu_sys::GuestAddr`
 --> libafl_qemu/src/modules/mod.rs:5:5
  |
5 | use libafl_qemu_sys::GuestAddr;
  |     ^^^^^^^^^^^^^^^^^^^^^^^^^^
  |
  = note: `#[warn(unused_imports)]` on by default

error: this `else { if .. }` block can be collapsed
   --> libafl_qemu/src/modules/usermode/snapshot.rs:742:16
    |
742 |           } else {
    |  ________________^
743 | |             if self.auto_reset {
744 | |                 self.reset(qemu);
745 | |             }
746 | |         }
    | |_________^
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#collapsible_else_if
    = note: `-D clippy::collapsible-else-if` implied by `-D clippy::all`
    = help: to override `-D clippy::all` add `#[allow(clippy::collapsible_else_if)]`
help: collapse nested if block
    |
742 ~         } else if self.auto_reset {
743 +             self.reset(qemu);
744 +         }
    |

    Checking libafl_intelpt v0.15.0 (/home/runner/work/LibAFL/LibAFL/libafl_intelpt)
warning: this lint expectation is unfulfilled
   --> libafl_qemu/src/executor.rs:305:10
    |
305 | #[expect(clippy::type_complexity)]
    |          ^^^^^^^^^^^^^^^^^^^^^^^
    |
    = note: `#[warn(unfulfilled_lint_expectations)]` on by default

[rmalmain]

i think in the long run we want to completely remove this and leave this job to EmulatorDriver

[rmalmain]

i don't think we should duplicate this comment. maybe put this as a module-level documentation?