The click sounds like the solenoid activating. That is a plus at least.
How are the wiring connections to the starter....not just the earth?
The fact the starter turns when "jumping" should mean it is ok and the problem is elsewhere.
How fast does the starter/ engine turn when jumped? Does the engine start up and run?
Have you checked ALL the earth connections? Battery to ground, starter to ground? Try a long jump lead direct from battery neg to starter mounting bolt. That bypasses your existing earths. Don't use thin wire!!! Connecte starter end first before battery end! If the bypass cures then it is an earth problem.
No cure suggests ignition switch or wiring issues.
