Modernize MuonDet

• prefer pragma once
• remove redundant inline specifiers
• avoid redundant copying of data
• remove rendundant parathesis
• add const
• remove redundant this->
• prefer std::abs over fabs
• prefer range based loops
• limit scope of variable declarations
• prefer direct member initialization
• prefer anonymous namespaces over static
• prefer fmt::format over ostrstream
• remove redundant data member