feat: AsyncPipeline that can schedule components to run concurrently

[mathislucka]

Related Issues

• to be merged after: fix: pipeline run bugs in cyclic and acyclic pipelines #8707

Proposed Changes:

Implements an AsyncPipeline that supports:

• running pipelines asynchronously
• step-by-step execution through an async generator
• concurrent execution of components whenever possible (e.g. hybrid retrieval, multiple generators that can run in parallel)
• sync run-method with concurrent execution of components

How did you test it?

• unit tests
• adapted behavioral tests to use Pipeline and AsyncPipeline

Notes for the reviewer

Review after #8707
Code was reviewed here before: deepset-ai/haystack-experimental#180

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: and added ! in case the PR includes breaking changes.
• I documented my code
• I ran pre-commit hooks and fixed any issue

[coveralls]

Pull Request Test Coverage Report for Build 13159781039

Warning: This coverage report may be inaccurate.

This pull request's base commit is no longer the HEAD commit of its target branch. This means it includes changes from outside the original pull request, including, potentially, unrelated coverage changes.

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• For a quick fix, rebase this PR at GitHub. Your next report should be accurate.

Details

• 0 of 0 changed or added relevant lines in 0 files are covered.
• 20 unchanged lines in 2 files lost coverage.
• Overall coverage increased (+0.9%) to 92.232%

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Files with Coverage Reduction	New Missed Lines	%
core/pipeline/pipeline.py	1	96.43%
core/pipeline/base.py	19	94.59%

Totals
Change from base Build 13141979385:	0.9%
Covered Lines:	9059
Relevant Lines:	9822

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💛 - Coveralls