windows: add virtual key codes and console input consts

[aymanbagabas]

This adds console input related key codes and consts

[gopherbot]

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[gopherbot]

Message from Gopher Robot:

Patch Set 1:

(1 comment)

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Please don’t reply on this GitHub thread. Visit golang.org/cl/621495.
After addressing review feedback, remember to publish your drafts!

[gopherbot]

Message from Ayman Bagabas:

Patch Set 1:

(1 comment)

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Please don’t reply on this GitHub thread. Visit golang.org/cl/621495.
After addressing review feedback, remember to publish your drafts!