Update ERC-7786: Extend ERC 7786 to support PULL communication mode

[philippecamacho]

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[eip-review-bot]

File ERCS/erc-7786.md

Requires 1 more reviewers from @amxx, @cjcobb23, @ernestognw, @frangio, @sergeynog

[github-actions[bot]]

The commit b566adbdca2947c4d9511dc8958734137574fb95 (as a parent of c10aac8ecbf3518c51919141fe9b077864746b76) contains errors. Please inspect the Run Summary for details.