Compress the PoV block before sending it over the network (#2288)

* Compress the PoV block before sending it over the network

This pr changes the way we send PoV blocks over the network. We now
compress the PoV block before it is send over the network. This should
reduce the size significant for PoVs which contain the runtime WASM for
example.

* Preallocate 1KB

* Try something..

* Switch to zstd and some renamings

* Make compression/decompression fail in browsers

* Use some sane maximum value

* Update roadmap/implementers-guide/src/types/network.md

Co-authored-by: Andronik Ordian <[email protected]>

* Fix and add test

* add

Co-authored-by: Andronik Ordian <[email protected]>
Co-authored-by: Robert Habermeier <[email protected]>