ImageService: Create Functional tweak API

[iJungleboy]

I'm submitting a

[x] feature request

...about

[x] Image Service, Img, Picture

Current Behavior / Expected Behavior

ATM most variations are specified through parameters of the method, but the method get's too big and hard to document / understand.

Goal is to create a Tweak API to gradually replace the many parameter names.

Your environment

• 2sxc version(s): 18.02