Rsync support file format and priv key as parameter

[mateodurante]

This change improves the functionality of the rsync bot parameters.

Now it is able to receive an optional ssh private key to connect the rsync. I saw this approach more reasonable than adding ssh keys to the server because all collector bots have the keys in their own configuration.

It is also capable of parsing directory path and file path with delta time date. It's useful when you have to open a file with the current date in its path.

Here's a picture of the setup working:

I hope these changes are useful. Thanks for your work