Replaced Creation Floating Action Buttons for Observations

[Bonsai8863]

Proposed changes

• Replaced FAB for creation of Observables, Artifacts, Indicators, and Infrastructures.

Checklist

• [x] I consider the submitted work as finished
• [x] I tested the code for its functionality
• [x] I wrote test cases for the relevant uses case (coverage and e2e)
• [ ] I added/update the relevant documentation (either on github or on notion)
• [x] Where necessary I refactored code to improve the overall quality