Refactor shared_ptr & container.h

[Vafo]

shared_ptr

• [ ] add make_shared
• [ ] consider conversion of argument to referred type (is it done in std ?)
• [ ] cover FIXME's and TODO's
• [ ] refactor in general and challenge ideas

container.h

• [ ] revise ideas
• [ ] refactor code

[Vafo]

• [ ] Decoupled testing of shared_ptr and containers, not related to "under development" calculator_impl
• [ ] Allocator and Deleter with custom behaviour (conversions / single block (control block + offset + object))