Put configuration values together

The program has literals that are of a configurative nature. Regard the code below:
`do {`
` threshold(workOriginal, binaryImage, binaryThreshold, 255, THRESH_BINARY);`
` binaryThreshold -= 20;`
` } while (!ImageHelper::IsBlackTextWhiteBackground(binaryImage) && binaryThreshold > 0);`

The 255 and the 0 are literals, and should be so. The 20 however might need to be changed in the future since it is a literal that might need to be configured.

- [ ] Compile all configurative values in one single class.

In the future it might be useful to load these values from an external file which the user can edit (if needed).

Search the C++ sources for binaryThreshold, the threshold call, and other configurable literals. Start with the shown ImageHelper::IsBlackTextWhiteBackground flow, then identify where the configuration class should be shared. Done means the configurable values are collected in one class without replacing intentional literals such as 255 and 0.

Written by the indexing model from the issue text.