[Security Solution] [Bug] User gets an undefined error when whitespaces are entered for markdown text for the document under Knowledge base

[muskangulati-qasource]

Describe the bug
User gets an undefined error when whitespaces are entered for markdown text for the document under Knowledge base

Kibana/Elasticsearch Stack version

VERSION: 8.17.0
BUILD: 80364
COMMIT: e3c75d19d796c366aedc5788960b2c6cc868014f

Pre Conditions

1. Kibana v8.17.0 build be must be available

Steps

1. Kibana version 8.17.0 or above should exist
2. Navigate to Stack management under Management section
3. Navigate to Kibana >> AI Assistants
4. Click on Manage settings for Elastic AI Assistant for Security
5. Navigate to the Knowledge base tab
6. Create a new document and give whitespaces as the markdown text of document and fill rest details accurately
7. Observe the error

Expected Result
User should not be able to create a Knowledge base entry with whitespaces as markdown text and there should be no error for the same

Screen Recording

Security AI settings.zip

[elasticmachine]

Pinging @elastic/security-solution (Team: SecuritySolution)

[muskangulati-qasource]

@amolnater-qasource please review!

[amolnater-qasource]

Reviewed & assigned to @MadameSheema