Add enabled field to VMPolicy

This indicates wheather the policy is enabled by user

Signed-off-by: walteryang <walteryang47@users.noreply.github.com>
Add getScheduleVms in VmPolicyDAOImpl

The function query enabled vm policies

Signed-off-by: walteryang <walteryang47@users.noreply.github.com>
Change DAO to Implementation classes

As the code is simple now, no need for interfaces

Signed-off-by: walteryang <walteryang47@users.noreply.github.com>
Add task_status field to Task

It indicates the status of the task execution

Signed-off-by: walteryang <walteryang47@users.noreply.github.com>