Causing: Rename Node-Effects and Edge-Effects

[Holger-Bartel]

This issue is for Causing.

Because of an historical notation, see https://realrate.ai/download/publications/RealRate%20Kausalanalyse%20mit%20NN.pdf, we use names and variable names that are too complicated from our point of view today. See See Sections 3.3 Exogene finale Effekte, 3.4 Endogene finale Effekte, and 4.3 Partieller, totaler und finaler Graph. So we should rename the variables in the public Causing repository https://github.com/realrate/Causing like this:

Node effects

exj_indiv -> xnodeeffect
eyj_indiv -> ynodeeffect

exj_indivs -> xnodeeffects
eyj_indivs -> ynodeeffects

Edge effects

eyx_indiv -> xedgeeffect
eyy_indiv -> yedgeeffect

eyx_indivs -> xedgeeffects
eyy_indivs -> yedgeeffects

Also, please check, if we use those names in the RealRate-Private repository.