Explicitly specify which logger should log

[matbun]

itwinai.loggers.LoggersCollection allows to log using multiple loggers at the same time. However, it is not possible for the users to select which logger should log when calling the log(...) method, resulting in all loggers in the collection to log simultaneously.

Maybe we could index each logger in the collection with a name (defaults to __class__.__name__) and use it to explicitly specify which logger should log what in the log(..., loggers=['cool_mlflow', 'nice_wandb']).