Add missing codec detection and warning message in video preview

[lei9444]

Summary of the Pull Request

This PR adds support for detecting missing video codecs during video file preview, and displays a warning message to inform the user when the required codec is not installed.

Changes

• Added GetMissingCodecAsync to detect unsupported video formats using MediaEncodingProfile and CodecQuery.
• If a required codec is missing, display a warning in the preview UI.
• Added localized string MissingVideoCodec_WarningMessage:

  "This video uses the {0} format, which isn't supported. Please install the required codec to play it."

• Add Store Search

PR Checklist

• [x] Closes: https://github.com/microsoft/PowerToys/issues/39235, https://github.com/microsoft/PowerToys/issues/38201
• [ ] Communication: I've discussed this with core contributors already. If 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 for new binaries
  • [ ] WXS for installer for new binaries and localization folder
  • [ ] YML for CI pipeline for new test projects
  • [ ] YML for signed pipeline
• [ ] Documentation updated: If checked, please file a pull request on our docs repo and link it here: #xxx

Detailed Description of the Pull Request / Additional comments

Validation Steps Performed

To simulate a missing codec (e.g., AV1):

1. Check if the AV1 extension is installed:

   Get-AppxPackage -Name *AV1*
   

2. If installed, remove it:

   Get-AppxPackage -Name *AV1* | Remove-AppxPackage
   

3. Use Peek to preview a video encoded in AV1 format.
4. Confirm that a warning message is shown indicating the missing codec.

[lei9444]

/azp run

[azure-pipelines[bot]]

Azure Pipelines successfully started running 1 pipeline(s).

[lei9444]

/azp run

[azure-pipelines[bot]]

Azure Pipelines successfully started running 1 pipeline(s).

[cinnamon-msft]

New UI looks good to me :)