Thermal Photons Production in $${{\pi }^{ + }}{{\pi }^{ - }} \to \gamma {{\rho }^{0}},$$ $${{\pi }^{ \pm }}{{\rho }^{0}} \to \gamma {{\pi }^{ \pm }}$$ and $${{\pi }^{ + }}{{\pi }^{ - }} \to \gamma \gamma $$ Processes