GH-69 add project key support

[alexhung]

Closes #69

• Add support for 'project_key' attribute to watch and policy
• Update operational risk policy documentation with HCL example

[github-actions[bot]]

CLA Assistant Lite bot:
Thank you for your submission, we really appreciate it. Like many open-source projects, we ask that you all sign our Contributor License Agreement before we can accept your contribution. You can sign the CLA by just posting a Pull Request Comment same as the below format.

---

I have read the CLA Document and I hereby sign the CLA

---

2 out of 3 committers have signed the CLA.
:white_check_mark: @alexhung
:white_check_mark: @jfrogsolutioncicd
:x: @JFrog Pipelines Step
JFrog Pipelines Step seems not to be a GitHub user. You need a GitHub account to be able to sign the CLA. If you have already a GitHub account, please add the email address used for this commit to your account.
_{You can retrigger this bot by commenting recheck in this Pull Request}