clickhouse: extraConfig should be an attrset

[srid]

services-flake/nix/clickhouse.nix

Lines 29 to 33 in 9b806b5

	extraConfig = lib.mkOption {
	type = types.lines;
	description = "Additional configuration to be appended to `clickhouse-config.yaml`.";
	default = "";
	};

This type makes the user specify raw config (an error-prone process as well):

      services.clickhouse."clickhouse-db" = {
        extraConfig = ''
          http_port: 8123
        '';
      };

But ideally it should be using freeformType (pkgs.formats.yaml). See example here. Because, then the user can just write:

      services.clickhouse."clickhouse-db" = {
        extraConfig.http_port = 8123;
      };