BI-2967: Wire frontend VCF genotype upload limit through environment config

[humsika]

Description

Story: BI-2967

This PR updates the Genotype Data Import frontend to use the deployment-configured VCF upload size limit.

Summary of changes:

• added frontend support for the configured genotype VCF upload limit from environment config
• updated the error message to display the active configured maximum size in MB
• added safe fallback handling when the configured value is missing or invalid
• kept the existing genotype import flow unchanged for valid files

Dependencies

bi-web: feature/BI-2967
bi-api: develop

Testing

• open the Genotype Data Import page
• select a .vcf file smaller than the configured limit and verify upload proceeds normally
• select a .vcf file larger than the configured limit and verify:
  • upload is blocked before the API request is sent
  • the user sees an error message showing the configured max size in MB

Checklist:

• I have performed a self-review of my own code
• I have tested my code and ensured it meets the acceptance criteria of the story
• I have commented my code, particularly in hard-to-understand areas
• I have either updated the source of truth or arranged for update with product owner if needed https://breedinginsight.atlassian.net/wiki/spaces/BI/pages/1559953409/Source+of+Truth
• I have run SiteImprove on pages impacted by changes