community[minor],langchain[minor]: Move base classes and reference implementations to core #12230

Job	Run time
Check linting	6m 34s
test-exports / exports-cjs	3m 43s
test-exports / exports-esm	3m 45s
test-exports / exports-esbuild	3m 50s
test-exports / exports-cf	3m 51s
test-exports / exports-vite	3m 38s
test-exports / exports-vercel	3m 32s
test-exports / exports-tsc	3m 50s
	32m 43s

Provide feedback