County and city selection enhancements

[catileptic]

• [ ] Populate the city drop-down with all available cities corresponding to a "county" selection.
• [ ] @RaduCStefanescu will provide us with the list of cities-per-county needed.
• [ ] Disable the "city" drop-down until the user has selected a county in the "county" drop-down. Once a user has selected a county, enable the city drop-down and only list the cities within that county.
• [ ] The city drop-down should be ordered alphabetically, but the top city in the list should be "reședința de județ".
• [ ] In the admin panel, the user should follow a similar pattern. The county drop-down is enabled and the city drop-down is disabled until the user has selected the county. After the user has selected the county, only cities within that county are listed, alphabetically, with "reședința de județ" at the very top.