[WD-19802] Redirect copydoc extension to content system

[muhammad-ali-pk]

Done

• Fetch supported projects from the content system
• Redirect the copydoc link to the corresponding webpage's details page in content system (for supported projects)
• For others, keep redirecting to the google document

QA

• Check out this branch
• Copy the code inside copydocs.js
• Open any url on our websites, e.g., canonical.com, ubuntu.com, juju.is etc.
• Open devtools, and paste the code in the console
• Click on the "copy document` link
• Verify the following
  • For supported projects (canonical.com and ubuntu.com), it takes you to cms
  • For others, it takes you to the google document

[akbarkz]

@muhammad-ali-pk Please add details about this change to the README as well.

[bartaz]

I'm not sure what consequences this change will have on the review/release process of the extension.

So far, the extension was self-contained. All it's code and functionality was within its codebase.
This change requires an API call to an external resource. This may mean (I'm not sure) additional access rights may be asked from user or additional checks/attention will be put into this during the review process when publishing it to stores. Both Chrome and Firefox stores have a bit different approach and rules. I don't know if it will matter, but I wanted to flag, that it may.

[muhammad-ali-pk]

@bartaz I'm not sure either if it would require additional permissions, but let's tackle it ad-hoc if it does. Thanks for pointing it out though.