fix some encoding error and some parsr construct extend_community error

[chenailin11]

Refactor some extend communities of nlri. They are:

"route-target:65530:1",
"route-target:1.1.1.1:1",
"route-target:1048576:1",
"route-origin:1048576:1",
"route-origin:65530:1",
"route-origin:1.1.1.1:1",
"redirect-nexthop:1.1.1.1:1",
"traffic-rate:65530:1",
"redirect-vrf:65530:1",
"traffic-marking-dscp:200,100",
"color:100",
"encapsulation:1,2",
"router-mac:22-22-22-22-22-22",
"es-import:22-22-22-22-22-22",
"esi-label:1:100",
"mac-mobility:1:100",
"traffic-action:S:1,T:1"

[xiaopeng163]

can you please add some unittest code into https://github.com/smartbgp/yabgp/blob/master/yabgp/tests/unit/message/attribute/test_extcommunity.py

thanks

[zlpqingmei]

@chenailin11