Draft: Structured parameters and buffer dependencies - Part I

The long-term goal for this MR is to allow a Gaudi-like syntax for algorithm and reduce the number of input/outputs, making configuration and algorithm definitions more user-friendly and maintainable. As this goal involve a lot of changes in the backend, and in the user-facing api, this MR will be split in 2 parts. The first part focuses on the backend changes, while the 2nd will implement features that need change to all algorithms and lines.

Goals for part I:

• Implement reference counted shared buffer to manage data dependencies
• Decouple store and memory managers => remove tags from memory managers, make them behave like standard allocators
• Also free host arguments when their lifetime ends (there is no distinction between host and device in the scheduler, it is now part of the type)
• Make the output handler a functional algorithm
• Merge Host and device store => Remove HostBufferManager
• Add memory visualisation tool

Goals for part II:

• Decouple argument and buffer classes => allow storage of any struct in arguments
• Group together relevant buffers to reduce the number of input/output of algorithms
• Make algorithms adopt Gaudi's std::tuple<Out...> operator(In...) syntax
• Remove set_argument_size => do reserve directly in operator()

FYI @raaij @dovombru @cagapopo @sponce @graven @clemenci

Updated main loop: