Update locales.js for support pl language

[fcientymeh]

Needed for translating FormatMessage format to pl language

Description

Issues Resolved

Screenshot

Testing the changes

Check List

• [x ] All tests pass
  • yarn test:jest
  • [] yarn test:jest_integration
• New functionality includes testing.
• New functionality has been documented.
• Update CHANGELOG.md
• Commits are signed per the DCO using --signoff

[fcientymeh]

Can anyone help me with pull request, and DCO problem?
I have send this first pull request, but there is some problem with github/DCO:

My name in profile was Andrzej M., but during commit with adding Signed-off-by..., the dot(.) on the end of username was removed.
So, my name, and Signed-off in commit were not the same (see screen above).

Is this is a bug in github?
If the dot (.) is not permitted in username, it shoud be checked during creating/editing profile maybe...