refactor: migrate tool discovery to Drupal plugin system

Giorgi Gagoshidzerequested to merge
issue/mcp_server-3560497:3560497-migrate-and-merge into 1.x

Replace custom ToolApiDiscovery service with a proper Drupal plugin architecture for MCP tools:

  • Add ToolPluginManager, ToolPluginInterface, ToolPluginBase, and Tool attribute for plugin-based tool discovery
  • Add ToolApi plugin that wraps Tool API module tools
  • Update McpBridgeService to use ToolPluginManager
  • Update McpToolConfigForm and ToolAutocompleteController
  • Remove ToolApiDiscovery service and its test
  • Update test fixtures and assertions for new tool ID format

Closes #3560497

Merge request reports