adding ECG raw data with R-R peaks

[PeterGamma]

For respiratory rate estimation in Matlab R-R peak sensor raw data are required:

https://www.mathworks.com/matlabcentral/fileexchange/55289-respiratory-rate-estimation

Adding this feature to a training tracker would reduce the amount of apps which have to run in parallel to record, HR, steps, respiratory rate, HRV, brain waves, etc.