[Quick Accent] Add Belarusian Latin and Belarusian Cyrillic character sets (#48344)

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fix/what does it change/how was it tested (even manually, if necessary)?
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## Summary of the Pull Request
This PR adds support for Łacinka (Belarusian Latin) and Belarusian
Cyrillic character sets to Quick Accent.

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## PR Checklist

- [x] Closes: #36571
<!-- - [ ] Closes: #yyy (add separate lines for additional resolved
issues) -->
- [ ] **Communication:** I've discussed this with core contributors
already. If the work hasn't been agreed, this work might be rejected
- [ ] **Tests:** Added/updated and all pass
- [x] **Localization:** All end-user-facing strings can be localized
- [ ] **Dev docs:** Added/updated
- [ ] **New binaries:** Added on the required places
- [ ] [JSON for
signing](https://github.com/microsoft/PowerToys/blob/main/.pipelines/ESRPSigning_core.json)
for new binaries
- [ ] [WXS for
installer](https://github.com/microsoft/PowerToys/blob/main/installer/PowerToysSetup/Product.wxs)
for new binaries and localization folder
- [ ] [YML for CI
pipeline](https://github.com/microsoft/PowerToys/blob/main/.pipelines/ci/templates/build-powertoys-steps.yml)
for new test projects
- [ ] [YML for signed
pipeline](https://github.com/microsoft/PowerToys/blob/main/.pipelines/release.yml)
- [ ] **Documentation updated:** If checked, please file a pull request
on [our docs
repo](https://github.com/MicrosoftDocs/windows-uwp/tree/docs/hub/powertoys)
and link it here: #xxx

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or any additional comments/features here -->
## Detailed Description of the Pull Request / Additional comments
This is a standard character set addition, with new entries in the
Language enum, the sets themselves added to CharacterMappings.All and
new resource strings for the user-facing names in the Settings page.

<!-- Describe how you validated the behavior. Add automated tests
wherever possible, but list manual validation steps taken as well -->
## Validation Steps Performed
(Manual tests.)
- Confirmed that the new character set entries were present in the Quick
Accent settings page list.
- Tested that each of the characters in both the sets could be selected
and typed.

.github/actions/spell-check/expect.txt

@@ -119,6 +119,7 @@ Badmode
 Badparam
 bbwe
 BCIE
+Belarusian
 BESTEFFORT
 bezelled
 bhid