[Counties] Import / export counties

[aniri]

Add the possibility of importing & exporting the counties list from admin.

Option only allowed for the master admin account (an ngo admin belonging to an ngo that has the organizer flag set to true)

Backend part was implemented in code4romania/monitorizare-vot#253.

UI available here: https://www.figma.com/file/61NHR7fwmV1Dsv4Pb6F8T7/code4ro_mv_user-management_2018.04.21-(Copy)?node-id=754%3A0

• add the button for exporting the current counties list, the button should be available on top of the counties list; use the endpoint GET api/v1/county/csvFormat - downloads existing county info in csv format
• add the button for importing the counties list, the button should be available on top of the counties list; use the endpoint POST api/v1/county/import - for importing the csv file

Counties data model:

• id, code, name, numberOfPollingStations, Diaspora flag, Order

Please use bootstrap classes as much as possible and avoid adding custom css styles to keep the codebase clean & consistent. The new UI should be as similar as possible to the one in figma, not pixel perfect.

Also, make sure all texts are extracted in translation files.

[aniri]

Here's an example of the new UI for this page :)