[Nix] Provide nix way of starting MariaDB

Summary: Provide nix native way of creating a MariaDB database

Test Plan:
From any branch, on a darwin (MacOS) machine:

nix run 'github:commE2E/comm?ref=jonringer/mariadb#mariadb-up'

Reviewers: ashoat, varun, abosh, atul

Reviewed By: varun, abosh

Subscribers: ashoat, tomek, adrian

Differential Revision: https://phab.comm.dev/D4750