Refactoring Skills NuGet Packages

[shawncal]

Motivation and Context

Currently, a user must acquire both the Microsoft.SemanticKernel.Skills package and, for most skills, a separate Microsoft.SemanticKernel.Connectors.* package. It's not clear that this is needed, nor is it clear what Connector you'd need.

Description

Changes:

• Microsoft.SemanticKernel.Connectors.* packages are all changed to the Microsoft.SemanticKernel.Skills.* namespace for increased discoverability
• Each connector is packaged under its skill namespace, i.e.
  • Microsoft.SemanticKernel.Connectors.Bing becomes Microsoft.SemanticKernel.Skills.Web

Contribution Checklist

• The code builds clean without any errors or warnings
• The PR follows SK Contribution Guidelines (https://github.com/microsoft/semantic-kernel/blob/main/CONTRIBUTING.md)
• The code follows the .NET coding conventions (https://learn.microsoft.com/dotnet/csharp/fundamentals/coding-style/coding-conventions) verified with dotnet format
• All unit tests pass, and I have added new tests where possible
• I didn't break anyone 😄

[dluc]

packages tested, looking also at the nested dependencies. LGTM

[lemillermicrosoft]

LGTM