add a ca_counties table for fk relationships to counties in other tables

[rkiddy]

There is going to be a lot of variability here. For example:

mysql> select county, countyname from alw_care_coordination_agencies limit 10;
+----------------+-----------------------+
| county         | countyname            |
+----------------+-----------------------+
| KERN           | Kern County           |
| SAN BERNARDINO | San Bernardino County |
| Los Angeles    | Los Angeles County    |
| LOS ANGELES    | Los Angeles County    |
| Sacramento     | Sacramento County     |
| San Bernardino | San Bernardino County |
| VENTURA        | Ventura County        |
| Los Angeles    | Los Angeles County    |
| El Dorado      | El Dorado County      |
| Los Angeles    | Los Angeles County    |
+----------------+-----------------------+

... and why do we have both a county and countyname column here? Wierd.

I also need a way to safely add the column, checking if the column is already there.