chore(prepopulation): Move prepopulation files on features/prepopulate_p...

...rofiles
Prepopulate app folder is on superdesk project and the intention is to keep the live blog related files on live blog project repo. 
Because of this now the files are relative to project root and in this way the files will be part of the project repo.
Also the intention was to reduce the number of required settings and in this way there is not needed any additional setting.