WIP: Use FakeKeyedContainer in Track v1
/!\ Experimental.
The idea is to progressively remove the keyed containers from HLT2. This MR introduce a FakeKeyedContainer that implement the same interface as a KeyedContainer but remove the concept of keys.
This allows to add the same element to multiple containers without having to make a copy of it but imply that we cannot use the object key anymore.
Changes needed in:
Edited by Arthur Marius Hennequin