Introduce a <SIDE_EFFECT_IMPORTS> tag

[oumar-fall]

Is your feature request related to a problem?
It can be useful to move side-effectful imports (import "module";) to the top of the imports to ensure the side-effects are executed first.

Describe the solution you'd like
A solution could be to have a tag (similar to <THIRD_PARTY_MODULES>) to be able to specify a specific position for such imports.

Describe alternatives you've considered
it can also be a boolean flag in the options.

[ice-cap0]

+1 would be awesome. still haven't managed to pull it off