[cardoe]

A baremetal port with local_group_information is bonded. Derive its
port-channel name from the first local_link_information entry and store
it under local_group_information["lag"] in the binding profile, so
update_port_postcommit and delete_port_postcommit can read it.

The number is stateless: 1000 + port*10 + D, where D is the breakout lane
(0 if absent) plus 5 for the second switch of a pair. Only fixed-form
leaves are supported: slot must be 1, port 1-308, lane 1-4.

update_port_precommit generates the name when none is present and writes
it to the active binding inside the port update's transaction; an anchor
that cannot be named aborts the update. PortContext only holds a snapshot
of the binding, and ML2 drops profile changes made in bind_port, so the
write goes through the plugin context. Ports bound before this change
have no stored name, so postcommit derives it for them.

[github-actions]

Python test results

497 tests   497 ✅  4s ⏱️
  1 suites    0 💤
  1 files      0 ❌

Results for commit 7212b51.