Add Unit Tests for Account Processor Filter Logic

The account processor's filter logic in account.rs lacks comprehensive unit tests, making it difficult to verify its correctness for various filter configurations.

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Problem

The process_account_update function contains filter logic with multiple paths based on account selection criteria. However:

• These different paths and edge cases are not fully covered by unit tests.
• Changes to the filtering logic risk breaking functionality without proper test coverage.

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Required Changes

1. Create unit tests in crates/windexer-geyser/src/processor/account.rs to cover:

   • Wildcard filters ("*")
   • Specific account filters
   • Owner filters
   • Combinations of account and owner filters
   • Edge cases, such as:
     • Empty filters
     • Invalid accounts

2. Documentation:

   • Add comments for each test case explaining what it is testing and why.

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Implementation Hints

1. Use the Rust #[test] attribute to define unit tests.
2. Mock any required dependencies or inputs for the process_account_update function.
3. Example test structure:

   #[test]
   fn test_wildcard_filter() {
       let result = process_account_update("*", /* other params */);
       assert!(result.is_ok());
       // Add additional assertions for expected behavior
   }
   

4. Write separate tests for each filter type and edge case.

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Acceptance Criteria

• Unit tests added for all filter types (*, specific accounts, owners, combinations).
• Edge cases (e.g., empty filters, invalid accounts) are covered.
• Each test is documented with clear explanations.
• Tests pass successfully without modifying existing functionality.