Add the possibility to delete elements for admins

# Add the possibility to delete elements for admins

## Context

Currently, you can delete a Root cause, Teams or Full Cycle but if there is a link to existing executions or problems, it will keep them.

## Expected

Restrain the delete of those components to Project admins only (will make this issue depends of #19 ).
If the deleted element is linked to existing others, then display a confirmation pop-up which ask if the admin wants to keep those elements but remove the reference to the deleted target, or if the admin wants to delete all the elements in cascade.