Change Propagation error

re #6538
Add WavelenghtPixel dependent parameter for Q1D

TODO: ensure that the input is valid.

re #6529
Creation of Algorithm SANSSolidAngleCorrection

This algorithm was created as a python script to allow the scientist
to check the algorithm and evaluate this feature. There are still things
TODO:

 * documentation of this algorithm
 * implement this algorithm in C++
 * validating input
 * error propagation

But, it allows testing the new feature.

re #6529
Implement the Wide Angle correction

re #6529
Correct the SolidAngleCorrection Algorithm

Change the label to twoTheta and correct the exception message

re #6529
Adjust the Unit Test for propagation error Q1D2

re #6538