Correct & rich handling of all clickEvent text

[Ellivers]

Example command:

tellraw @s {"text":"test","clickEvent":{"action":"suggest_command","value":"/item modify enti"}}

This does not cause the function to fail to load, so it should not cause an error. A warning would be more acceptable.

While an invalid command with the run_command action does not cause the function to fail either, it has more reason to cause an error, since clicking the text and therefore running the command would do so.