Modernize MuonAlgs

• minimize scope of variables
• add [[nodiscard]]
• remove redundant inline qualifiers
• prefer STL algortihms
• prefer range-based loops
• prefer auto over ...::iterator
• remove commented out code
• remove redundant destructors
• remove redundant protected qualifiers
• prefer std::array over C-style arrays
• prefer std::unique_ptr over raw pointers and delete
• remove unused variables
• add const
• prefer pragma once

must be applied in conjunction with LHCb!2300 (merged) and Lbcom!414 (merged)