Adding ethernet support

[Foxei]

We have added Ethernet support to the mros2-esp32 project. The required changes closely resemble the code in the microROS project. Additionally, I have included a Kconfig.projbuild file to facilitate the switching between interfaces and configuration of the interfaces as needed.

[takasehideki]

@Foxei We deeply apologize that we couldn't reply to this your PR for a long time,,, To be honest, we have been busy with other tasks and have been away from mros2 development for a while, so I was not aware of your great contribution,,, I hope you can forgive me.

As you may have noticed, we have received another PR #27 similar to your proposal. I think the difference is whether the use of Ethernet is applied to the whole or the individual example.
I assume that we usually think of the Wi-Fi communication when we want to employ the ESP32 family, and that using Ethernet is not a so common case. For this reason, I think it is better to provide a dedicated guide for those who wish to use it for this special case.
Also, I believe the instructions should be as easy as possible. Some first-time users may be unfamiliar with menuconfig and may feel uneasy. This is also the reason why IPv6 can be disabled using only standard operations with idf.py (see here).

If you are still interested in adding this feature, I would be glad to receive your comments and suggestions at #27 .

[takasehideki]

By the way, your commit to bump mros2 v.0.53 is very interesting.
4e03ea4

I think you could confirm this worked fine. So I will create another PR to track this.