python-preview bug fix for 6-memory-and-embeddings #165

Describe the bug
fix some codes for running semantic-kernel/samples/notebooks/python/6-memory-and-embeddings.ipynb
memories = await kernel.memory.search_async(memory_collection_name, ask, limit=5, min_relevance_score=0.77)
will returns empty list because there is missing codes in semantic-kernel/python/semantic_kernel/memory/semantic_text_memory.py

and output printing parts should be changed.

To Reproduce
run semantic-kernel/samples/notebooks/python/6-memory-and-embeddings.ipynb

Expected behavior
semantic-kernel/samples/notebooks/python/6-memory-and-embeddings.ipynb runs well

Screenshots
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Desktop (please complete the following information):

• OS: Mac M1
• IDE: VS code
• NuGet Package Version [e.g. 0.1.0]

Additional context
Add any other context about the problem here.