feat(cs-client): Add CsClient app to registry

[lxgr-linux]

This adds the CsClient app to the registry that "Generates a C# client library for your cosmos-sdk blockchain".

I also want to claim the app challenge bounty like mentioned here.

Feel free to comment on anything I might have overlooked.

[Pantani]

@lxgr-linux, can you please update with the latest version of the main? We add a workflow to validate the app's JSON files. Thank you for the contribution. We are finishing our review of the code soon.

[lxgr-linux]

@Pantani, I updated the PR and I'm looking forward to ur review.

[julienrbrt]

Hi @lxgr-linux, thank you for sticking around. @toschdev is reviewing and testing your change.
We will let you know if you got awarded a bounty and how much.

[lxgr-linux]

@julienrbrt I'm looking forward

[julienrbrt]

I've reviewed your app.
lgtm!

[lxgr-linux]

Nice, I think @Pantani also has to approve since he requested changes on this PR.

[julienrbrt]

@lxgr-linux we will contact you at the email mentioned in this PR about the bounty.

[michelleellen]

Hey @lxgr-linux I contacted you via email but haven't heard back. Could you share again the best email to reach you? Thanks

[lxgr-linux]

Hello @michelleellen,
I've double checked and I haven't received anything from you yet. Alternatively you can reach me via peer.meyer.3141@protonmail.com.
Greetings

[lxgr-linux]

@michelleellen I'm looking forward to your mail.

[michelleellen]

@lxgr-linux I have followed up with the new email address provided, let me know if you receive it. Thank you