Add custom exceptions for better error-handling

[willtai]

Description

This PR adds custom exceptions to replace the usage of ValueError in various places as they were unambiguous and not informative to the user. Here is a way to think about the added exceptions:

• Retriever-related exceptions:
  • RetrieverInitializationError: used in __init__() method of retrievers.
  • SearchValidationError: used in .search() method of retrievers.
  • FilterValidationError: used in validation of fields for metadata filtering.
  • EmbeddingRequiredError: used when an embedder is required for the retriever.
  • RecordCreationError: used when returning VectorSearchRecord. This will probably change with Retriever results #45
• Database-related exceptions:
  • Neo4jIndexError: Used for index handling methods
  • Neo4jVersionError: Used when Neo4j version does not meet minimum requirements

Additionally, new types are specified for the WeaviateNeo4jRetriever to be used for data validation. This enables it to raise exceptions similarly to the Neo4j retrievers.

The documentation is updated to include the errors.

Type of Change

• New feature
• Bug fix
• Breaking change
• Documentation update
• Project configuration change

Complexity

Complexity: Low

How Has This Been Tested?

• Unit tests
• E2E tests
• Manual tests

Checklist

The following requirements should have been met (depending on the changes in the branch):

• Documentation has been updated
• Unit tests have been updated
• E2E tests have been updated
• Examples have been updated
• New files have copyright header
• CLA (https://neo4j.com/developer/cla/) has been signed

[willtai]

@CodiumAI-Agent /update_changelog

[CodiumAI-Agent]

Changelog updates: 🔄

2024-05-29

Added

• Introduced custom exceptions for improved error handling, including RetrieverInitializationError, SearchValidationError, FilterValidationError, EmbeddingRequiredError, RecordCreationError, Neo4jIndexError, and Neo4jVersionError.
• Added new types for WeaviateNeo4jRetriever to support data validation and exception handling.

Changed

• Replaced ValueError with custom exceptions across various modules for clearer and more specific error messages.

Fixed

• Updated documentation to include new custom exceptions.

to commit the new content to the CHANGELOG.md file, please type:
'/update_changelog --pr_update_changelog.push_changelog_changes=true'

[stellasia]

Looks good! (just double check the print in my comments above if you can, the rest is very minor)