Display warning message during install/first setup of Azure MCP extension when organizational policies are set to disable mcp

[kvenkatrajan]

When organizational policies are disabled or not set in github, the enablement of mcp servers are set to disable by default.

The Policy Diagnostics viewer in VSCode shows -
| chat_preview_features_enabled | false |
| chat_agent_enabled | true |
| mcp | false |

When users install the Azure MCP, we need a way of displaying a warning via toast notification or other ways to alert the user on this behavior -

Sample message "Your organizational policies have MCP servers disabled. Please contact admin for access" or something to that effect. @charris-msft please feel free to suggest appropriate verbiage

Here's an example of what VSCode does today to display organization level setting -

CC: @g2vinay , @joshfree , @charris-msft