minor code changes for better readability

[manthan127]

refactor: simplify VNDetectRectanglesRequest & AVCaptureVideoOrientation initialization

What

• Simplified rectangle detection request creation by removing an unnecessary closure:

  let rectangleDetectionRequest = VNDetectRectanglesRequest(completionHandler: { request, error in
      ...
  })

  instead of:

  let rectangleDetectionRequest: VNDetectRectanglesRequest = {
      let rectDetectRequest = VNDetectRectanglesRequest(completionHandler: { request, error in
          ...
      })
      return rectDetectRequest
  }()

• Simplified enum initialization in AVCaptureVideoOrientation by assigning enum cases directly:

  self = .portrait

  instead of:

  self.init(rawValue: AVCaptureVideoOrientation.portrait.rawValue)

Why

• These changes reduce verbosity and make the code easier to read and maintain.
• Behavior remains identical; this is purely a readability and style improvement.

How

• Replaced closure-based initialization with direct assignment.
• Replaced .init(rawValue:) usage with direct enum case assignment.

Testing

• Verified functionality manually (rectangle detection and orientation mapping).
• No change in logic, so no additional tests required.

Risks

• Minimal; only refactoring for clarity with no behavior changes.

Feedback welcome on whether this style aligns with project conventions or if further adjustments are needed.