Make use of View Binding

As an intermediate step to #3146 i propose to use [View Binding](https://developer.android.com/topic/libraries/view-binding) (this is **not** Data Binding).

- It will save you *lots* of code
- It is recommended
- It provides compile time null safety and type checks
- It can be used partially to the current used `findViewById()`-method, no big bang required
- It matches the current technology stack and will be an easy first step to a cleaner architecture

I think Data Binding is still interesting, but it requires huge efforts to make it work nicely everywhere, while View Binding is the "little brother" - better than the current state but way easier to switch compared to Data Binding.

I'd like to hear your opinions @tobiasKaminsky @AndyScherzinger @ezaquarii

If everyone agrees i could create a initial Pull Request to add support in a few cases to demonstrate it on a concrete sample.