[Counties] Bulk edit counties

[aniri]

Add the option of selecting and editing more counties at the same time.

Depends on #216

The option should only be available for master admins (organizer flag set to true).

Backend part was implemented in code4romania/monitorizare-vot#254 . The endpoint for editing counties is POST api/v1/county/{id}

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

• add the possibility of selecting the counties in the list
• upon selection, the following bulk actions should be available delete and set as first

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.