refactor: prompt system (#1154)

.changeset/tall-kangaroos-sleep.md

examples/prompts/promptMixin.ts

examples/readers/src/csv.ts

examples/readers/src/llamaparse-json.ts

packages/core/package.json

packages/core/src/prompts/base.ts

packages/core/src/prompts/index.ts

packages/core/src/prompts/mixin.ts

packages/core/src/prompts/prompt-type.ts

packages/core/src/prompts/prompt.ts

packages/core/src/schema/index.ts

packages/core/src/schema/type/base-output-parser.ts

packages/core/src/utils/index.ts

packages/core/src/utils/llms.ts

packages/core/src/utils/object-entries.ts

packages/core/tests/prompts.test.ts

packages/core/tests/prompts/mixin.test.ts

packages/llamaindex/src/ChatHistory.ts

packages/llamaindex/src/OutputParser.ts

packages/llamaindex/src/PromptHelper.ts