addons: bond: add support for es-sys-mac and es-bonds

addons: bond: add support for es-sys-mac and es-bonds

ES bonds have the same "init state" requirements as CLAG bonds -
1. A bond needs to be designated as an "es-bond" for this purpose.
For clag-bonds we used "clag-id" attr (to designate a bond as a "clag-bond").
For ES bonds we will use "es-sys-mac" attr.

2. Slaves added to an "ES bond" must have protodown-on.
This is again similar to CLAG bonds

3. And vice-versa i.e. when a slave is removed from an "es-bond",
protodown-on must be cleared.

4. When es-sys-mac is first set on a bond, all the bond-slaves must be
placed in "protodown-on" state. This is needed whether FRR is running at that point or not.

Signed-off-by: Julien Fortin <julien@cumulusnetworks.com>