Clean up War Thunder StateSource: remove SkipInvalidFrames and fix code issues

[Copilot]

Addresses review feedback from PR #17 to simplify the War Thunder StateSource implementation and fix identified code quality issues.

Changes

• Removed SkipInvalidFrames feature: Eliminated the filtering logic and related properties (SkipInvalidFrames, InvalidFrameLogInterval) from StateSourceOptions and StateSource. All frames are now yielded directly from the HTTP polling base class.

• Removed unused field: Deleted _lastInvalidFrameLog from StateSource that was declared but never used.

• Fixed always-false condition: Changed else if (!hasData) to else in HttpPollingSourceBase (line 192 was checking !hasData after already checking hasData in the if branch).

• Bumped StateData DataVersion: Updated from (1,0,0) to (2,0,0) to reflect the breaking change where Valid field changed from int to bool.

• Simplified nested conditionals: Combined nested if statements in demo code from:

  if (data.Valid)
  {
      if (frameCount % 1 == 0)
      {
          DrawDashboard(data);
      }
  }

  to:

  if (data.Valid && frameCount % 1 == 0)
  {
      DrawDashboard(data);
  }

The simplified StateSource now just passes through all telemetry data without filtering, making the behavior more predictable and the code easier to maintain.

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