Duplication of margin and padding helpers

[rpowis]

Are these necessary? If not, they should be consolidated and the corresponding markup refactored.

https://github.com/hmrc/assets-frontend/blob/master/assets/scss/base/_helpers.scss#L35-L85

[gavinwye]

We need to investigate this and find out which services these classes are being used in and why they are being used.

[rpowis]

In order to get rid of these for good, we should work out which are the most commonly used and incorporate them into the component and patterns they're being used for.

[gordonmcmullan]

These no longer appear in the v4.x.x line of releases, closing this issue