Support dynamic values via field substitution for the opsgenie_addr field

[mohamedelema17]

Description

Checklist

• I have reviewed the contributing guidelines.
• I have included unit tests for my changes or additions.
• I have successfully run make test-docker with my changes.
• I have manually tested all relevant modes of the change in this PR.
• I have updated the documentation.
• I have updated the changelog.

Questions or Comments

Unit test is not necessary as the current tests sufficiently cover this small change.

[jertel]

Thanks for the submission. Unit tests are required, even for this small change. It should be possible to modify an existing test to prove that the to_addr is dynamically updated with the match data.

[mohamedelema17]

@jertel I have added the unit test

[jertel]

Thank you. It looks like the build failed due to some whitespace linting checks. Please review the build output. Once you get this to pass we can get it merged in. make test-docker will give the same failure and results, so you can use that to verify before you push.

[jertel]

One more:

 ./alerters/opsgenie_test.py:1275:39: E231 missing whitespace after ','