Allow entering "City, State" and pass "State" (if present) as "state code" to the API

[dave-burke]

The main input for the "one-call" API from OpenWeatherMap is lat/lon coordinates, so that's what we should consider the canonical location.

Storing the city/state is just for user-friendly display.

Tasks

• [ ] Add location.stateCode to store.ts.
  • [ ] Update the state object to add stateCode to location.
  • [ ] Update src/store/types.ts as well.
  • [ ] Add a SET_STATE_CODE mutation to store/mutations.ts and a matching function in the store.ts mutations: { } section.
• [ ] In LocationPicker.setCity, if the new value contains a comma, call city.split(',') and store the first value as location.city (per current behavior) and the second as location.stateCode in the store (using the new SET_STATE_CODE mutation). Both values should be trimmed of surrounding whitespace (probably in the store mutation functions).
• [ ] Use the geolocation API to update the lat/lon coords in vuex whenever the city/state change.

[dave-burke]

The OpenWeather API has a location query endpoint that takes comma delimited city, state, country, so there's no reason for us to do this kind of parsing.

This is being replaced by another story to implement more robust location picking like in the mock up.