Enable Spice with an absolute pointing device in the test suite guest

Initial results suggest that this greatly increase robustness when running the test suite in a nested VM setup (e.g. on lizard) or when using the snapshot improvements of #8008 (closed)/#6094 (closed). Presumably the absolute pointer results in higher accuracy, and fewer lost (or “messed up”) mouse events.

Feature Branch: test/9425-enable-spice-and-asbolute-pointing-device

Parent Task: #8539 (closed)

Original created by @anonym on 9425 (Redmine)