Implement IBucket.open() method in Python lib

[asuiu]

Develop an open() method within the IBucket interface that returns a file-like object, mimicking the functionality of Python's built-in open() function for interacting with objects in a bucket-based storage system.

Functional Requirements:

• Object Access: The method must accept a parameter that uniquely identifies the object within the bucket (e.g., object key or path).
• Modes: Implement support for both read ('r', 'rb') and write ('w', 'wb') modes.
• File-Like Object: The returned object must implement the following methods, mirroring Python's file object:
  • Read Mode: read(), readline(), readlines(), seek(), tell(), close().
  • Write Mode: write(), flush(), close();
    • seek() is not supported in write mode.
• Binary and Text Modes: Support both binary ('b') and text modes, handling encoding/decoding as necessary.
• Buffered Operations: Implement buffered read/write operations for efficiency, utilizing flush() to commit writes.
• Error Handling: Implement appropriate error handling for scenarios such as:
  • Object not found.
  • Insufficient permissions.
  • Invalid mode.
  • Connection errors.

Acceptance Criteria:

• The open() method must return a file-like object that behaves consistently with Python's built-in open() for the supported modes.
• Read operations must accurately retrieve object content.
• Write operations must correctly persist data to the bucket.
• Binary and text modes must function as expected.
• Buffered operations and flush() must operate correctly.
• Appropriate exceptions must be raised for error conditions.