Is it possible to obtain the lift and drag coefficients of a 3D body in ANSYS Fluent?
Yes this is possible, and it is the way lift and drag of aircraft are estimated in the pre-design phase. There is detailed methodology described in Synthesis of Subsonic Airplane Design by E. Torenbeek, Appendix E. for lift and pitching moment, Appendix F. for drag.

For lift and pitching moment, first the wing characteristics are estimated based on known research and on corrections for fuselage length, wing/body interference length etc.

For drag, first the $C_{D_0}$ of all components in the table underneath are determined, and then the lift of the wing, body, tailplane etc as function of angle of attack are added.