Create publishToNuGet library

[gaiksaya]

The dot net artifacts like the net client is published on Nuget.
Add jenkins library that publishes the artifacts under https://www.nuget.org/profiles/opensearchproject namespace

Acceptance Criteria:

• The library should sign the given artifacts
• Publish to NuGet automatically (without any human intervention)

[gaiksaya]

As of today we have https://github.com/opensearch-project/opensearch-net client that publishes the artifacts on nuget.
Got some information from @Xtansia that all clients in that repository will be released at the same time.

[gaiksaya]

Some information on how to publish to nuget using command line and api key https://learn.microsoft.com/en-us/nuget/nuget-org/publish-a-package#push-by-using-a-command-line

[gaiksaya]

The security approved signing process for Nuget was causing issues for this automation. Currently, we were creating .dll files, signing them and then packing them to .nupkg files that were finally released to the customers. However, following #1234 we are trying to avoid building anything on jenkin and signing can only happen on jenkins for now.

We tested the following theory (thanks @prudhvigodithi for the suggestion):

Create .nupkg packages and provide them as release candidates via GHA. The above library will do the following:

1. Download them and Convert them to .zip (just a rename)
2. Unzip them and sign the .dll files
3. Zip them again
4. Rename to .nupkg

@Xtansia helped us test this theory and the packages worked as expected. We will be going forward with this solution.
Thanks!

cc: @wbeckler @VachaShah @bbarani @Yury-Fridlyand

[gaiksaya]

There was a change in plan. Unzipping and packing the artifacts back again gave a number of permission issues on various files. It felt a lot of risky and kind of hacky, so we are making an exception for dotnet clients. We will be building, signing and releasing all on same platform using jenkins.
See the above PR in review. Thanks!