MultiThreaded Tesseract OCR

IronTesseract 2021 previously had a ReadMultithreaded method to allow .NET developers to read images and PDFs more efficiently.

This is no longer needed in 2022. All IronOCR image processing and OCR reading operations are multithreaded and do not require the developer to use a special API.

IronTesseract will automatically attempt to use all threads available on all cores, and will consider responsiveness on the main / GUI thread elegantly.