Use consistent padding in storage pool details

The storage pool field "Name" has a 10px left padding, but the other
detail fields do not.

Apply the same left padding value to the other storage pool details.

Signed-off-by: Crístian Viana <vianac@linux.vnet.ibm.com>
Center the storage pool "Actions" button

The "Actions" button is not center aligned, it is slightly closer to the
left margin than to the right margin.

Improve the storage pool details appearance by aligning the "Actions"
button.

Signed-off-by: Crístian Viana <vianac@linux.vnet.ibm.com>