STP Port Config #60

[rahul-1475]

Issues:

• STP Port Config - (orca_nwlib) Payload and path are defined in SONiC Player Cell - "GET/SET/DELETE STP PORT" config parameters received on get operation on the path should be updated during discovery in the vlan node already being created in DB. Wouldn't be bad to append stp**** as prefix so that those parameters can be differentiated than other interface params.
• DB Updates (orca_nw_lib) - Interface specific path e.g. openconfig-spanning-tree:stp/interfaces/interface[name=Ethernet0]/config can be subscribed to receive notifications on any config change. Please note those subscriptions are interface specific which means subscription should be created for all interfaces for a device.
• orca_backend - REST end points to be updated.
• orca_backend - Respective Test cases covering CRUD operations on parameters.
• There should be an end-point resync (discover) STP global and port config not the complete device discovery, discovery function of STP from orca_nw_lib can be used for implementation.

Fixes:

• created new files stp_port.py, stp_port_db.py, stp_port_gnmi.py.
• added new apis for crud operations in stp_port.
• added subscription both on delete and add.
• add new tests cases to test each parameter.
• added new stp_port db. Attched stp_port to device, portchannel, interface with has relation.

Note: put api first delete gnmi config and then creates gnmi config. This is done to trigger subscription.

[rahul-1475]

orca_nw_lib pr: https://github.com/STORDIS/orca_nw_lib/pull/84