Use AsyncTask thread-safe logging helpers in MavenDownload

[Copilot]

MavenDownload derives from AsyncTask but still used six direct Log.Log* calls inside async/background execution paths. This updates those call sites to AsyncTask’s thread-safe logging helpers while preserving existing messages and XA error codes.

• Logging API alignment in MavenDownload

  • Replaced direct calls:
    • Log.LogMessage(...) → LogMessage(...) (3 sites)
    • Log.LogCodedError(...) → LogCodedError(...) (3 sites)
  • No text/code changes: all log message templates and XA4237/XA4252/XA4239 values remain unchanged.

• Scope intentionally constrained

  • Kept Log usages passed as an argument to helper APIs unchanged (GetRequiredMetadata, TryParseArtifactWithVersion, DownloadPayload), since those APIs require TaskLoggingHelper.

// Before
Log.LogMessage ("Found POM file '{0}' for Java artifact '{1}'.", primary_pom, artifact);
Log.LogCodedError ("XA4237", Properties.Resources.XA4237, artifact, ex.Unwrap ().Message);

// After
LogMessage ("Found POM file '{0}' for Java artifact '{1}'.", primary_pom, artifact);
LogCodedError ("XA4237", Properties.Resources.XA4237, artifact, ex.Unwrap ().Message);

[Copilot]

Pull request overview

This PR updates the MavenDownload MSBuild task (which derives from AsyncTask) to use AsyncTask’s thread-safe logging helper methods instead of calling TaskLoggingHelper.Log* directly from async/background execution paths.

Changes:

• Replaced Log.LogMessage(...) with LogMessage(...) at three call sites.
• Replaced Log.LogCodedError(...) with LogCodedError(...) at three call sites.