1. Fixed RTL icon margin in the studio
Cherry picked from our fork (https://github.com/Edraak/edx-platform/pull/64).
2. Make math equation fields always LTR in CAPA problems
This one is clear. Since all the equation input is in English, the field should be always LTR.
Cherry picked from our fork (https://github.com/Edraak/edx-platform/pull/74).