Draft: Fix M.2 socket wrong pin directions and missing pins

Fixes #3244 .

Work in progress

Specification: https://members.pcisig.com/document/download/19525 (Revision 5, v1.0, Requires membership)

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Socket connectors (Platform)

• Socket 1 (Connectivity Socket)
  • Key A
  • Key E
• Socket 2 (WWAN/SSD/Other Socket)
  • Key B
  • Key C
• Socket 3 (Drive Socket)
  • Key M

Screenshots

Key A

Key E

Key B

Key C

Key M

Edge connectors (Adapters)

• Socket 1 (Connectivity Socket)
  • Key A
  • Key E
  • Key A-E
• Socket 2 (WWAN/SSD/Other Socket)
  • Key B
  • Key C
• Socket 3 (Drive Socket)
  • Key M
• Key B-M

Screenshots

Socket 1 (Connectivity Socket)

Key A

TODO

Key E

TODO

Key A-E

TODO

Socket 2 (WWAN/SSD/Other Socket)

Key B

TODO

Key C

TODO

Socket 3 (Drive Socket)

Key M

TODO

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• Remove the instructional content of this template
• Provide a URL to a datasheet for the symbol(s) you are contributing
• An example screenshot image is very helpful
• Ensure that the associated footprints match the official footprint library
  • A new fitting footprint must be submitted if the library does not yet contain one.
• If there are matching footprint PRs, provide link(s) as appropriate
• Check the output of the automated check scripts - fix any errors as required
• Give a reason behind any intentional library convention rule violation.