`OpteAdm` duplicates a significant amount of code from `OpteHdl`

[FelixMcFelix]

Currently, ioctls are implemented identically between both OpteAdm (bin/opteadm/src/lib.rs) and OpteHdl(lib/opte-ioctl/src/lib.rs), and each has several ioctls that the other does not. All of this functionality should be implemented once on OpteHdl. OpteAdm could instead be used instead to contain any equivalent methods for CLI-specific types, if needed:

pub struct OpteAdm(OpteHdl);

impl Deref for OpteAdm {
    type Target = OpteHdl;

    fn deref(&self) -> &Self::Target {
        &self.0
    }
}

impl OpteAdm {
    // ... CLI-specific convenience/conversion methods ...
}