[3.x] Fix crash when tooltip_request_func object is freed

[timothyqiu]

3.x version of #53460.

• set_tooltip_request_func() is not exposed to scripts on 3.x, but the implementation is the same, so it's still crashable if something goes wrong in C++ code.
• ObjectID is a plain integer on 3.x, so it needs explicit initialization.

[akien-mga]

Sorry I'm the one who broke the build, in my shame I'm going to force push a fixup to the cherry-picked commit I pushed earlier.

[akien-mga]

Should be fixed now (you'll have to do some creative rebasing to remove the bad cherry-pick from your branch).

[akien-mga]

Thanks!