Refactor: Regex in clinvar.py

[berntpopp]

Description:
The regex used in clinvar.py to extract information from ClinVar data is complex and could be simplified. Simplifying the regex logic can make the code more readable and easier to maintain.

Proposed Solution:

• Review the current regex patterns and simplify them where possible.
• Consider breaking down the regex logic into smaller, more manageable parts.
• Add comments explaining the purpose of each regex pattern.