doc: release-notes: Add 4.0.0 release notes for networking

[rlubos]

Add 4.0.0 release notes for networking.

Ethernet && Wi-Fi TBD separately.

[mmahadevan108]

a frame instead of frame?

[kartben]

some typos or spelling mistakes but looking great!

I would also recommend putting the "Added" and "Implemented" items first in each bullet list, as one often wants to quickly skim through the release notes to spot what's new before potentially looking at bug fixes. As it stands, many of the sections start with what is possibly the least interesting change, like e.g. an assertion being fixed :)

[kartben]

Suggested change

	* Fixed handling of DNS responses encoded with captial letters.
	* Fixed handling of DNS responses encoded with capital letters.

[kartben]

Suggested change

	* Fixed checksum offloading cheks for VLAN interfaces.
	* Fixed checksum offloading checks for VLAN interfaces.

[kartben]

Suggested change

	* Fixed deprecated/preffered IPv6 address state transitions.
	* Fixed deprecated/prefered IPv6 address state transitions.

[kartben]

Suggested change

	* Separated native INET sockets implemnetation from socket syscalls so that
	* Separated native INET sockets implementation from socket syscalls so that

[rlubos]

Thanks @kartben, I've fixed the typos and reordered changelog entries as requested.

[rlubos]

As it stands, many of the sections start with what is possibly the least interesting change, like e.g. an assertion being fixed :)

Need to blame contributors here they did not fix issues earlier, the original order was simply based on the commit order in git log :)