feat: improve base tool type (#709)

examples/agent/openai.ts

examples/agent/react_agent.ts

examples/agent/step_wise_openai.ts

examples/agent/step_wise_react.ts

examples/agent/stream_openai_agent.ts

examples/toolsStream.ts

packages/core/e2e/node/openai.e2e.ts

packages/core/e2e/node/snapshot/agent.snap

packages/core/e2e/node/snapshot/gpt-4-turbo.snap

packages/core/package.json

packages/core/src/agent/openai/worker.ts

packages/core/src/agent/react/worker.ts

packages/core/src/tools/QueryEngineTool.ts

packages/core/src/tools/ToolFactory.ts

packages/core/src/tools/WikipediaTool.ts

packages/core/src/tools/functionTool.ts

packages/core/src/tools/index.ts

packages/core/src/tools/utils.ts

packages/core/src/types.ts

packages/core/tests/agent/OpenAIAgent.test.ts