Fix use after free with script timing in LuaMan.cpp

[Architector4]

In RunScriptFunctionObject, script timing is calculated before/after running the script, then written into PerformanceMan::m_ScriptTimings table based on the path to the script. This introduces a use-after-free error and likely crashing if the script in question deallocates the function object, like Combat Shield's "Detach" pie menu option deleting itself: #219

My fix here is to get the table entry before running the script, store a pointer to it in a variable, and then access it directly after running the script. This also removes the double lookup into the unordered_map.

In my testing, this fixes the issue entirely. I'm not knowledgeable on this codebase or on C++isms, I don't know what's the policy of the project on raw pointers, so if this doesn't fit, please feel free to disregard this and implement an equivalent kind of a solution in proper language etiquette instead lol

Fixes #219

[HeliumAnt]

Awesome!