Remove TRestxxxProcess/TRestMetadata (char *cfgFilename) constructor?

[jgalan]

Inside TRestDetectorHiitsToSignalProcess I found the following comment.

// __________________________________________________________
//     TODO : Perhaps this constructor should be removed
//            since we will allway load the config from TRestRun
//            when we use AddProcess. It would be necessary only if we use the
//            process stand alone but even then we could just call LoadConfig
//            __________________________________________________________
TRestDetectorHitsToSignalProcess::TRestDetectorHitsToSignalProcess(char* cfgFileName) {

I am now reviewing this process and I will remove that comment. Then, if this is a real concern we could create an issue, discuss it and apply the change.

The proposal implies that if we want to use the metadata/process class stand-alone we instantiate it and call LoadConfig.

@rest-for-physics/core_dev

[nkx111]

I believe the method LoadConfig, LoadDefaultConfig can also be removed. If we want to use the metadata/process class stand-alone we instantiate it and call LoadConfigFromFile, which is provided by TRestMetadata. I think it is worthy to do so. We can simplify a lot of code for the processes.