Add `gl-sm-pr-3 ` and `gl-sm-w-half` utility class

This utility class is being used for MR gitlab!52967 (merged)

.gl-sm-pr-3 {
  @media (min-width: $breakpoint-sm) {
    padding-right: $gl-spacing-scale-3;
  }
}

.gl-sm-w-half {
  @media (min-width: $breakpoint-sm) {
    width: 50%;
  }
}

.gl-md-ml-3 {
  @media (min-width: $breakpoint-md) {
    margin-left: $gl-spacing-scale-3;
  }
}

Please also remove this temporary class that was set here:

Edited Feb 26, 2021 by Samantha Ming