Enable Onvif discovery handler authenticated discovery

[johnsonshih]

What this PR does / why we need it:
refs #250
This PR enable Onvif DH to discover devices that require authentication. The schema of secret data is described in the doc PR
project-akri/akri-docs#78

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If applicable:

• this PR has an associated PR with documentation in akri-docs
• this PR contains unit tests
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• code builds properly (cargo build)
• code is free of common mistakes (cargo clippy)
• all Akri tests succeed (cargo test)
• inline documentation builds (cargo doc)
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