Improve OneNote File Extraction and Fix IOC Storage

[phutelmyer]

Summary of Change
This PR introduces some improvements to the ScanOnenote class in the strelka module and fixes the IOC feature to properly capture and store Indicators of Compromise (IOCs) in file events.

Changes Made

1. Added a new constant ONE_NOTE_MAGIC for the binary string to search for in the data.
2. In the ScanOnenote class, modified the scan method to capture statistics on the number of files processed and extracted.
3. Fixed the collection of IOCs during the scanning process.

Describe testing procedures
Tested ScanOnenote and AddIOC functionality with relevant scanners and files.

Sample output
N/A

Checklist

• My code follows the style guidelines of this project
• I have performed a self-review of and tested my code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings