[frontend] fix content mapping view

[frapuks]

Proposed changes

• use the good answer in ternary if searchTerm is undefined

Checklist

• [ ] I consider the submitted work as finished
• [x] I tested the code for its functionality
• [ ] I wrote test cases for the relevant uses case
• [ ] I added/update the relevant documentation (either on github or on notion)
• [ ] Where necessary I refactored code to improve the overall quality

Further comments

• this is the continuation of the PR : https://github.com/OpenCTI-Platform/opencti/pull/6152