Implement the remaining TODO fixes

[jscarle]

Summary

• replace the item sharing API with a breaking ShareItem(...) -> ItemShareResult design that supports unrestricted links
• trim the CLI version output, document item hydration clearly, and add a release draft for the next x.x.x release
• add regression coverage for archive behavior, share command construction, version trimming, and adding a new field to an existing item

Breaking changes

• ShareItem(...) now returns ItemShareResult instead of void
• the single-email overloads were removed; pass a collection for restricted links or omit recipients for unrestricted links

Testing

• dotnet test OnePassword.NET.Tests\\OnePassword.NET.Tests.csproj -m:1

Closes #90
Closes #91
Closes #93
Closes #94