Adapt code for TypeScript 3.7
Created by: felixfbecker
Migrate code to work with TS 3.7. This means if the build fails for our nightly upgrade Renovate PR, it is a compiler bug.
Created by: felixfbecker
Migrate code to work with TS 3.7. This means if the build fails for our nightly upgrade Renovate PR, it is a compiler bug.