Use Literal type for attributes with fixed deterministic values (e.g., blood_group)

[8figalltimepro]

Description:
Some model attributes in pesuacademy-py, such as blood_group, have a fixed set of known deterministic values.
Currently, these are typed as str, which is too generic and does not provide compile-time validation or IDE auto-completion for allowed values. Additionally, during profile parsing (in _ProfilePageHandler._parse_profile_soup), we should validate that the extracted blood_group exactly matches one of the allowed values before storing it.

Proposed Change:

• Replace str annotations with Literal where applicable.
  Example:

  from typing import Literal
  
  blood_group: Literal["A+", "A-", "B+", "B-", "AB+", "AB-", "O+", "O-"]

• In _ProfilePageHandler._parse_profile_soup, check that the parsed blood_group exactly matches one of the allowed values before assigning it to the model.
• Review all models for similar attributes and update accordingly.

Benefits:

• Improves type safety and reduces risk of invalid values.
• Enhances developer experience with better auto-completion and inline documentation in IDEs.

[SakshamBajpayi]

hello, id like to work on it

[8figalltimepro]

Please use it everywhere applicable not just blood_group