LPS-42537 Sort main_rtl.css

Hey Nate,

@brianchandotcom asked me to review the sorting of this file. At first I thought it was right, but then I realized that it should follow the SASS pattern as it's not yet a generated CSS. The goal of this file is to add manual changes to the control panel theme for RTL languages in cases that cannot be solved by the automatic process. Could you please verify the sorting is now correct?

Thanks!