* Refactor and move all v2 related code to under the v2 namespace.
Most of the changes are around imports and restructuring of the
codebase. While it looks like a lot of code was added, most of the code
already existed and was simply moved or copied over to v2. The only
exceptions are:
- under kfp/v2/components/component_factory.py: some helper functions
were copied with simplification from _python_op.py
- we no longer strip the `_path` suffix in v2 components.
Note: there is still some duplication of code (particularly between
component_factory.py and _python_op.py), but it's ok for now since we
intend to replace some of this with v2 ComponentSpec + BaseComponent.
* Update setup.py.
* update tests.
* revert accidental change of gcpc
* Fix component entrypoint.
* Update goldens.
* fix tests.
* fix merge conflict.
* revert gcpc change.
* fix tests.
* fix tests.
* Add type aliases for moved files.
* merge and update goldens.
Yaqi Ji
Chen Sun
Ajay Gopinathan
Yuan (Bob) Gong