feat: add support for callables as a tokeniser in InMemoryDocumentStore

[CarlosFerLo]

Related Issues

• fixes Accept Callables as Tokenizers for InMemoryDocumentStore #4720

Proposed Changes:

How did you test it?

Notes for the reviewer

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 9110932852

Details

• 0 of 0 changed or added relevant lines in 0 files are covered.
• 10 unchanged lines in 1 file lost coverage.
• Overall coverage decreased (-0.06%) to 90.526%

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Files with Coverage Reduction	New Missed Lines	%
document_stores/in_memory/document_store.py	10	96.18%

Totals
Change from base Build 9103206687:	-0.06%
Covered Lines:	6593
Relevant Lines:	7283

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💛 - Coveralls