Make use of tslib

[jrieken]

TypeScript generates lots of helpers for inheritance et al. They bloat up our code. We have some fragile regex tricks to remove unnecessary code. Since TypeScript support has gotten a lot better we should make use of tslib and the new emit flags

[jrieken]

Closing this without action because the fix for #24770 will check that our current solution works and leaving out helper at compile time will make development harder. Removing waste at bundling is the right point in time