Grafana: Consider removing the data path override

[mgyongyosi]

Consider removing the cfg:default.paths.data=#{HOMEBREW_PREFIX}/var/lib/grafana config override from the Grafana formula and use the grafana.db from the #{HOMEBREW_PREFIX}/share/grafana/data path.

I'm not a Homebrew expert, but if it's not strictly necessary to save the database to #{HOMEBREW_PREFIX}/var/lib/grafana then maybe we should get rid of this config override and use the database from the #{HOMEBREW_PREFIX}/share/grafana path which corresponds to the current --homepath configuration. So, no config override would be required for executing admin commands with the Grafana CLI.

Related: grafana/grafana#81033