Create additional filters (contains, TAG support)

[yedidyakfir]

Goal

Add more filter operators and Redis TAG support

Description

Extend the filter system with additional operators like contains, startswith, endswith, and Redis TAG field support.

Example

users = await User.find(User.email.contains('@example.com')).to_list()
users = await User.find(User.tags.has('premium')).to_list()

Acceptance Criteria

• Implement contains filter operator
• Implement startswith filter operator
• Implement endswith filter operator
• Add Redis TAG field type support
• Add tests for new filter operators
• Document the new operators