[Gf] add constrained residual minimization dyson solver

[the-hampel]

• add l2 tau norm function from cppdlr
• add tests for l2 tau norm
• fix loss of prec warning in DLR tests
• add Python bindings for constructors of DLR meshes from other DLR meshes
• add constrained residual minimization (CRM) function to solve Dyson's equation https://arxiv.org/abs/2310.01266
• add tests for CRM Dyson solver

Example of the method for a 3orbital Bethe lattice test at n=0.8 filling with realistic QMC data at beta=1000 eV for D=1 (half-bandwidth):