C270 (or other) webcam clip to Anycubic i3 mega

**Update :**
There is an alternate clip module (new_i3_mega_clip with freecad source included).
It is simpler, easier to print (no support) and much smaller.
It is also a bit less sturdy.
With that setup you'll need : one arm, 2 bolt, the new_i3_mega_clip and the c270 base)
You *dont* need i3_mega_clip and arm_support

**Original text:**
This is a multipart webcam suppor for the anycubic i3 mega
It is clipped on the left side of the i3. It is a remix of several very nice projects, i j