Add SpaCy Processor for Enhanced NLP Support in Quivr

[Sahil-2101]

Description

Key Features:

• Introduced SpaCyProcessor to handle various file formats (PDF, DOCX, TXT, CSV)
• Supports recursive text splitting for chunked processing
• Applies spaCy NLP pipeline for tokenization and entity recognition on file content

Motivation:
Adding spaCy provides Quivr with advanced NLP features that will improve downstream tasks requiring text analysis, making the processing of varied document types more powerful.

Note:
This feature requires spaCy and a compatible language model (e.g., en_core_web_sm).

Checklist before requesting a review

Please delete options that are not relevant.

• My code follows the style guidelines of this project
• I have performed a self-review of my code
• I have commented hard-to-understand areas
• New and existing unit tests pass locally with my changes
• Any dependent changes have been merged

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