Update instances of `gl-loading-icon` from numeric to string size

Overview

With the recent update of the loading spinner component in gitlab-ui (gl-loading-icon in gitlab-ce), the size property has been updated from being numeric (1 - 5) to string (sm, md, lg).

The updated component handles converting the numeric property to the correct string based value but we need to work on refactoring all instances of gl-loading-icon where a numeric property is being specified.

This will allow us to completely remove all the additional code added to the component in order to handle the automatic conversion.

Proposal

Have individual teams / stage groups update instances of gl-loading-icon which fall under their scope as follows;

• size of 1 will be converted to sm (shouldn't be specified anywhere as it's the default)

• size of 2 or 3 will be converted to md

• size of 4 or 5 will be to converted to lg

Links / references

Further information on the update of the spinner component can be found here.