[SessionService] Implement method that supports writing files

[joao4all]

Prerequisites

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Description

Currently, the SessionService class doesn't provide support for file writing. Implement methods to make it possible. Suggestion: WriteTransaction should receive a collection of file paths that will be written by the session. With that, it's possible to extend the CreateOrUpdateThings to receive a collection of file paths

Steps to Reproduce

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System Configuration

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• COMET version:
  • CDP4Web
• Environment (Operating system, version and so on): Windows
• .NET Framework version: -
• Additional information: