Add OAuth authentication support for MCP server integration with Copilot Studio

[Prajwal214]

Feature
Add feature issue reference

• Copilot Studio currently does not offer a Bearer Token option when connecting to an MCP server. It primarily supports OAuth and API Key based authentication.
  To ensure compatibility, the Collate MCP server needs to support OAuth authentication so users can successfully connect through Copilot Studio’s available authentication flow.

Describe the task
A clear and concise description of what the bug is.

• Implement OAuth authentication support in the MCP server to allow seamless integration with Copilot Studio.