New technique: Register SSH public key to project metadata

[xathrya]

What does this PR do?

• add new technique: Register SSh public key to project metadata

Lateral movement to any Cloud Compute instance by registering public key to project's metadata. This technique is affecting any instance on same project.

Motivation

This technique is developed as part of Grab's purple teaming activity and we want to share it so more people can get the benefit.

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Co-authored-by: Satria Ady Pradana [email protected]