Fix TypeScript type issues in examples

After adding type checking to examples through #2783, we've uncovered multiple types issues. Due to the size of that PR, they weren't fixed immediately.

There are multiple cast to `unknown` in the examples which should be fixed.

Start by reviewing the examples and the type-checking changes introduced in #2783, then locate the casts to `unknown`. Done means the example type issues are resolved and the examples pass type checking without the unnecessary casts.

Written by the indexing model from the issue text.