ceph-windows: Fix event log artifacts

ceph-windows: Fix event log artifacts

Previously, the windows event log artifacts were being dumped in
evtx format and then converted to txt by individually querying them
using wevtutil.

After doing this, the resulting txt logs contained xml entries that
omitted the actual event message.

Now, they will be directly dumped as txt using Get-WinEvent and the
evtx logs can be obtained using the -IncludeEvtxFiles flag.

Signed-off-by: Stefan Chivu <schivu@cloudbasesolutions.com>