Backport system name memoization

[LastTalon]

Current behavior

Currently in v0.8 system names rely on debug.info which is a somewhat costly operation.

Proposed improvement

Backport #134 to our LTS v0.8 branch in order to support this for users who are not yet ready to update to v0.9.

[jackTabsCode]

Re conversation in Discord: I ran into an error when hot-reloading a system after I made these changes. I'm not able to reproduce it, but due to it being such a small performance improvement anyway, I don't think it's worth backporting if potentially unstable.