Create possibility to decrypt container in memory and introduce MIME type value in the DataFile object

[stanislav-degtjarjov]

• Create possibility to decrypt container in memory
  Example of the decrypt return type:
  ListOf(
  DataFile{
  String name,
  long size,
  String mimeType, // NB! Should be introduced. Mime type of the file was added to the container
  Date creationDate, // creation date of the file was added to the container (if possible)
  byte[] body; //
  });

Proposal: We can create 2 types of DataFile objects, one is read once, and another is read multiple times.

[naare]

This is introduced in v1.3