Read and write files

[mechanik-daniel]

Files should be allowed to be written and read, with the following highlights:

• Path functions should be provided so it would not behave differently on different platforms
• Writing should be limited to a predefined (.env configured) folder and its subfolders
• Automatic format detection on read, the same way as it is done in the Designer
• [optional] User-defined format to parse with. Should include string and binary (base64) options in addition to the regular JSON, XML, CSV, HL7V2 etc.
• Should include functions for reading directories
• Should include functions for deleting files and directories