feat: add Go MCP server update API (#15261)

## What

#15240
implementation for PUT /api/v1/mcp/servers/:mcp_id

## Changes

- Adds the Go implementation for `PUT /api/v1/mcp/servers/:mcp_id`.
- Wires MCP service and handler into the Go server/router for the update
route.
- Preserves Python-style behavior for ownership checks, partial update
fields, MCP type/name/URL validation, `headers`/`variables`
normalization, and tool metadata scrubbing.

docker/launch_admin_service.sh

@@ -14,7 +14,7 @@ load_env_file() {
         echo "Loading environment variables from: $env_file"
         # Source the .env file
         set -a
-        source "$env_file" 
+        source "$env_file"
         set +a
     else
         echo "Warning: .env file not found at: $env_file"