Merge PR #45 "Add ServiceURL option for KMS client" and PR#46 "Version Bump & .NET 6"

[jnunn-aws]

Description

1. Merging chore: Upgrade test projects from .NET Core 2.1 to .NET 6, and version bump for upcoming release #46
   1. Upgrades the .NET Core 2.1 unit and integration test targets to .NET 6
   2. Also does a minor version upgrade in anticipation of releasing Add ServiceURL option for KMS client #45
2. Merging Add ServiceURL option for KMS client #45

Motivation and Context

Addresses Issue #29: AmazonKeyManagementServiceConfig doesn't use the service url when it's setting on AmazonS3CryptoConfigurationV2

Testing

Ran dotnet test locally, unit and integration tests passed.

Screenshots (if appropriate)

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist

• My code follows the code style of this project
• My change requires a change to the documentation
• I have updated the documentation accordingly
• I have read the README document
• I have added tests to cover my changes
• All new and existing tests passed

License

• I confirm that this pull request can be released under the Apache 2 license