Add V2 endpoint for aws/cfn/template/resources/authored

Commit 802e844 changed the response shape of aws/cfn/template/resources/authored from string[] to AuthoredResource[] (objects with logicalId and type). This broke backward compatibility with existing clients (VSCode extension, alpha canaries) that expect a string array.

This PR restores the original V1 endpoint returning string[] and introduces a V2 endpoint at aws/cfn/template/resources/authored/v2 returning AuthoredResource[].

Changes

• RelatedResourcesProtocol.ts — Reverted GetAuthoredResourceTypesRequest to string[], added GetAuthoredResourceTypesRequestV2 with new method path
• LspRelatedResourcesHandlers.ts — Added onGetAuthoredResourceTypesV2 handler registration
• RelatedResourcesHandler.ts — Restored original V1 handler (string[]), renamed existing handler to V2 (AuthoredResource[])
• CfnServer.ts — Registers both V1 and V2 handlers
• Tests — Added V1 handler tests, updated existing tests to reference V2, restored pre-802e844 test cases