feat: "import-data" event, patchMultipart

[ThisIsDemetrio]

Pull Request Type

• Bugfix
• Feature
• Code style update (formatting, local variables)
• Refactoring (no functional changes, no api changes)
• Build related changes
• CI related changes
• Documentation content changes
• Other... Please describe:

Description

Includes:

• event import-data to be used in case the application requests the import of documents from a file;
• method patchMultipart to support multipart upload of files with a PATCH request;

PR Checklist

• The commit message follows our guidelines included in the CONTRIBUTING.md
• Tests for the changes have been added (for bug fixes / features)
• Relevant CHANGELOG is updated

Does this PR introduce a breaking change?

• Yes
• No

Other information