This PR makes the "test" folder strict in typescript.
`pnpm build:test` before: Found 3275 errors in 174 files.
`pnpm build:test` after: Found 4912 errors in 268 files.
At some point we should bring that number to 0 and make it a requirement
in the CI. Currently `pnpm build:test` is not run anywhere in the CI.
Additionally, I took the opportunity to combine the duplicate
configurations from `tsconfig.json` and `tsconfig.typecheck.json` using
"extend".
declaration, declarationMap and sourceMap have been removed as they have
no reason to exist in noEmit.
The settings I left in `tsconfig.typecheck.json` are ones that I'm not
sure why they are there. Perhaps the file could be removed or at least
reduced further.
a304dc4b01