Update AutoGen Sample App | Rename AutoGen Assistant -> AutoGen Studio (#998)

* add new autogen-studio renamed folder

* remove old autogen-assistant files

* formatting updates

* add support for upsert/updates to agents and workflows

* version bump, general fixes

* support deleting db items

* add support for summary method to flowmanager

* formatting updates

* update serverl urls

* version bump

* add support for updated metadata messages object to include sender information

* formatting updates

* update documentation and blog post

* blog post update

* add description field example to agent workflow spec

* readme and blog update

* Update website/blog/2023-12-01-AutoGenStudio/index.mdx

Co-authored-by: Chi Wang <wang.chi@microsoft.com>

* add fix to ensure working directory is cleared after each run

* update version

* minor updates

* formatting updates

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Co-authored-by: Chi Wang <wang.chi@microsoft.com>