TN: some changes in west Tennessee

[neroute2]

US 51: SPkwyE -> SPkwy (or SouPkwy? see US 61)
US 51: I-240(30) -> I-240
US 51: TN14_E -> TN14_N
US 51: TN3 -> CheAve? 3 seems to be unsigned here
US 51: KerRd -> KerrRosRd
US 51: TN59_S -> TN59_E
US 51: move TN19_W to the connector
US 51: UniRd -> ToTN210?
US 51: TN183 -> TN183_S, TN183_End -> TN183_N
US 51: TN214_E -> TN214

US 61: SouPkwy -> SPkwy? (see US 51)

3: TN14_E -> TN14_N
3: 2ndAve_N -> 2ndSt_N

19: add LakeDr_E and move US51_N to where the connector meets US 51
19: move TN209 to the connector
19: US70/79_* -> US70_*? since US 79 is north-south
19: TN76_S -> TN76? it's not signed north of here

21: add CedSt for old 22 north?

59: US70/79_* -> US70_*? since US 79 is north-south

78: LevPhiRd -> CatLanRd

180: split in two between TN88_E (-> TN88) and TN209_S (-> TN209) since there are no signs showing an overlap; also 88: TN180/209 -> TN209 and TN180_S -> TN180, 209: TN180_N -> TN180 and TN88/180 -> TN88

181: add a shaping point at the south end so it loops over 88?

222: add points at each end of the realignment? I don't know what to call them - I guess ThoDr would work for the south end, but who knows if the north end is still StaSomRd or now KeeRd

[mapcat]

https://github.com/TravelMapping/HighwayData/pull/3870

There's a TN3 sign leading to that otherwise unsigned segment here.

TN 222 was realigned before usatn was activated, so I can add those points in the future for new users who need them but don't believe they serve a general purpose.