[Core] BaseObject: remove components from the slave list

[fredroy]

Related (and fix) : #5890

Description:
Searching for memory leaks, I detected big ones coming from TetrahedronFEMForcefield.
In particular the colorMap, which was supposed to be deleted in the destructor.
I noticed that the destructor was not called and then... asked Claude which found that slaves was keeping a reference to their owner, and so the reference counter of the Sptr was not at the end of the program (so not the dtor was not called).

Easy solution is to unlink the slaves during the cleanup phase (what is done in this PR)
Only problem is if a component is overriding this function and not calling super::cleanup() 💀
(template method design blabla for BaseObject blabla 🫠)

[with-all-tests]

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[fredroy]

[ci-build][with-all-tests]

[alxbilger]

I still cannot make up my mind if the responsibility to clean up slaves is on the base or derived class...

[bakpaul]

It depends what does the remove do when called. Does the slave run a callback that might act on the owner ? Is there any way this callback could access the owner ? If this is the case, IMO the safest way to go would be to make the most derived class to do this. But in the meantime if it is the case, I guess there is a design flaw.

So for me the best way to go is to make sure no such callback exists and the slaves never access their owner in the destructor and keep this in the BaseObject destructor