feat: extend pipeline.add_component to support stores

[ZanSara]

Related Issues

• fixes Change docstore connection in pipelines preview #5238
• blocked by feat: introduce Store protocol (v2) #5259

Proposed Changes:

• Changes the API of v2 Pipelines with respect to connecting docstores with components (see the issue for usage examples). The old API left all responsibility to the components, while the new API uses the pipeline as an intermediary for the connection.
• Creates two mixins to help the implementation of components requiring docstore(s): StoreMixin and MultiStoreMixin.
• Adapt MemoryRetriever to this new connection style
• Fix all tests and add new ones

How did you test it?

• local test run
• ci

Notes for the reviewer

Let's focus on how the API feels like both on the pipeline side and on the component side.

Checklist

• I have read the contributors guidelines and the code of conduct
• I have updated the related issue with new insights and changes
• I added unit tests and updated the docstrings
• I've used one of the conventional commit types for my PR title: fix:, feat:, build:, chore:, ci:, docs:, style:, refactor:, perf:, test:.
• I documented my code
• I ran pre-commit hooks and fixed any issue

[coveralls]

Pull Request Test Coverage Report for Build 5575173381

• 0 of 0 changed or added relevant lines in 0 files are covered.
• 11 unchanged lines in 2 files lost coverage.
• Overall coverage increased (+0.06%) to 45.542%

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Files with Coverage Reduction	New Missed Lines	%
preview/pipeline.py	2	95.0%
nodes/prompt/invocation_layer/hugging_face.py	9	91.47%

Totals
Change from base Build 5543286756:	0.06%
Covered Lines:	10562
Relevant Lines:	23192

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💛 - Coveralls

[silvanocerza]

This must not be part of the public interface of a component.

Suggested change

	supported_stores: List[Type[Store]] = [Store] # type: ignore # (see https://github.com/python/mypy/issues/4717)
	_supported_stores: List[Type[Store]] = [Store] # type: ignore # (see https://github.com/python/mypy/issues/4717)

[ZanSara]

I find this to be public API since all components will need to set it explicitly. I'll leave it without the underscore.

[silvanocerza]

Left some comments, I very much prefer if we force component creators to be explicit when defining which stores their component supports.