Set up a test suite that runs fluster in a virtual machine using virtme.
This test only runs when a kernel image path is set in the new
`virtme_kernel_image` meson option.
The kernel iimage must have support for visl.
The suite contains 4 tests, 1 for each supported codec in visl:
- vp8
- vp9
- h.264
- hevc
Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/5434>
