Use the tenant name as default organization name

This way we'll avoid having all tenant organizations named "CONSUL" by
default, and we'll also use different email senders per tenant, which
will reduce the change of the emails being marked as spam.

spec/models/setting_spec.rb

@@ -187,6 +187,20 @@ describe Setting do
     end
   end
 
+  describe ".default_org_name" do
+    it "returns the main org name for the default tenant" do
+      expect(Setting.default_org_name).to eq "CONSUL"
+    end
+
+    it "returns the tenant name for other tenants" do
+      create(:tenant, schema: "new", name: "New Institution")
+
+      Tenant.switch("new") do
+        expect(Setting.default_org_name).to eq "New Institution"
+      end
+    end
+  end
+
   describe ".default_mailer_from_address" do
     before { allow(Tenant).to receive(:default_host).and_return("consulproject.org") }