RunState: Rename enum values as generated by the QAPI

RunState: Rename enum values as generated by the QAPI

Next commit will convert the query-status command to use the
RunState type as generated by the QAPI.

In order to "transparently" replace the current enum by the QAPI
one, we have to make some changes to some enum values.

As the changes are simple renames, I'll do them in one shot. The
changes are:

 - Rename the prefix from RSTATE_ to RUN_STATE_
 - RUN_STATE_SAVEVM to RUN_STATE_SAVE_VM
 - RUN_STATE_IN_MIGRATE to RUN_STATE_INMIGRATE
 - RUN_STATE_PANICKED to RUN_STATE_INTERNAL_ERROR
 - RUN_STATE_POST_MIGRATE to RUN_STATE_POSTMIGRATE
 - RUN_STATE_PRE_LAUNCH to RUN_STATE_PRELAUNCH
 - RUN_STATE_PRE_MIGRATE to RUN_STATE_PREMIGRATE
 - RUN_STATE_RESTORE to RUN_STATE_RESTORE_VM
 - RUN_STATE_PRE_MIGRATE to RUN_STATE_FINISH_MIGRATE

Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>