[Feature Request] Get swept list without `hydra.main`

[clouds56]

🚀 Feature Request

Motivation

Is your feature request related to a problem? Please describe.

I'd like to manually get config from hydra, go without hydra.main

def get_config(args: list[str] | None = None) -> Config:
  import hydra
  from typing import cast
  if args is None:
    args = ["+llm=small", "+optim=adamw", "llm.batch_size=32"]
  with hydra.initialize(config_path=None, version_base='1.3'):
    cfg = hydra.compose(
      config_name=None,
      overrides=args
    )
  return cast(Config, cfg)

This works well but doesn't support multi-run. It would fail on get_config(["+llm=small,large", "+optim=adamw"])

Pitch

Describe the solution you'd like

have a hydra.compose_multi that have RunMode.MULTI_RUN, and returns a list[DictConfig]

Describe alternatives you've considered

manually parse and call sweeper.

  with hydra.initialize(config_path=None, version_base='1.3'):
    gh = GlobalHydra.instance()
    assert gh.hydra is not None
    parser = OverridesParser.create(config_loader=gh.hydra.config_loader)
    overrides = parser.parse_overrides(args)
    split_overrides = BasicSweeper.split_arguments(overrides, None)
    configs = [
      hydra.compose(
        config_name=None,
        overrides=o
      ) for o in split_overrides
    ]

Are you willing to open a pull request? (See CONTRIBUTING)
yes.

Additional context

Add any other context or screenshots about the feature request here.