feat: adding count with filtering operations toQdrantDocumentStore (#2803)

* feat: adding count with filtering operations to

* updating docstrings and removing extra param filters from get_metadata_field_min_max

* updating count_unique_metadata_by_filter to receive multiple metadata fields instead of only one

* catching exception and logging error

* refactoring code into helper functions to reduce duplicated code

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Co-authored-by: David S. Batista <dsbatista@gmail.com>

Author: srini047