mgr/cephadm: rework how _process_ls_output builds a DaemonDescription

mgr/cephadm: rework how _process_ls_output builds a DaemonDescription

Previously, the _process_ls_output function would create an
DaemonDescription and then assign values to attributes one-by-one.  This
prevents the class from doing any data type/value conversions unless we
resort to more complex approaches like descriptors or `__setattr__` for
example. Update the _process_ls_output function to build a
DaemonDescription using keyword args so that we have the opportunity
later to convert data passed to it in `__init__`.

Signed-off-by: John Mulligan <jmulligan@redhat.com>
(cherry picked from commit 1fd4132c7c03602719f29230732b12c8afa04779)