[JENKINS-71789] Enable ${variable} support for email and cc fields

[mikecirioli]

See JENKINS-71789 for reproducer and details

Advisor had default support for escaping ${VAR} expressions in the email configuration field, but otherwise did not support resolving variables for email or cc values, and would not correctly encode ${VAR} as {^${VAR} if used as a CC value.

This PR enables encode/decode support for the email and cc values fields.

Testing done

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[mikecirioli]

ping @aheritier for review please!

[aheritier]

LGTM thanks @mikecirioli

there is a spotbugs issue https://ci.jenkins.io/blue/organizations/jenkins/Plugins%2Fcloudbees-jenkins-advisor-plugin/detail/PR-198/1/pipeline/44

[aheritier]

please use mvn spotless:apply to fix the formatting @mikecirioli

[aheritier]

All good. Thanks a lot !!!

[PierreBtz]

Lgtm thanks