Fix Bourns 3314 SMD potentiometer pin numbers

Also other fixes:

• change to rounded SMD pads
• V7 model path variable
• Fix overlapping and not-quite vertical F.Silk lines
• Make pad-silk clearance 0.2mm up from 0.18mm
• Add orientation feature to 3314S side-access variant
• Add access hole to 3314R-GM5 extended-leadframe bottom-ajust variant

Fixes: #2604 (closed)

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DS: https://www.bourns.com/docs/Product-Datasheets/3314.pdf

3314R-GM5 new hole:

KLC seems clear.

Question: Should 3314R-1 actually be 3314R-x, as it covers -1, -2, -3 and -4 (just not -GM5)? I have put "single slot" in the description to match -1 and the graphic. Or make a -2 for the cross recess variant too and add to the Fab layer?