Custom tlv info support

[Vibaswan]

Fixes #393

Change of oui-subtype field in get_states LLDP Custom TLV node from string to unit32

Adding support for information field in LLDP custom TLV learned info

Redocly Link

basically everything remains same just an addition of property information in path States.Response/LldpNeighbhors.State/LldpCustomTLV.State

snappi-snippet

# request
request = api.states_request()
request.lldp_neighbors.lldp_names = []
response = api.get_states(request)

# response
neighbors = response.lldp_neighbors
neighbor = neighbors [0]
neighbor.custom_type  # type: unit32 example_value- 0
neighbor.oui  # type: hex_string example_value- "0:80:C2"
neighbor.oui_subtype  # type: uint32 example_value- 1 
# newly added
neighbor.information # type hex_string example_value- "0030ae"

[apratimmukherjee]

Minor changes is desc.
Add Issue and link.
snappi python snippet to access new field.
Note gnmi PR TBD later for completion.