Add an API: GET /eligible-jurisdiction?state=

[syk1112]

Step 1 of #42

• Create an api endpoint returning all the eligible counties Courtbot serves in Oklahoma via an api call /eligible-jurisdiction?state=OK. Response should return:

{
    "jurisdiction_type": "city" | "county" | "ward" | "zip_code" | "state",
    "eligible_juridisdictions": [
        // should be eligible values of the jurisdiction_type
        // e.g. "city" jurisdiction type lists eligible cities "Tulsa", "Muskogee", "Roger" etc
        // "zip_code" jurisdiction type lists eligible zip codes 74133, 74012, 74114
    ]
}

• Should be able to change the value in state param in the URL to get the state's eligible jurisdictions as mentioned in Ask brigades to stand up an API endpoint of counties/jurisdictions #40

[kendallcorner]

I think I will try to look at this in my spare time.