Modify DB schemas for Geo support for Packages::Nuget::Symbol

What does this MR do and why?

This is the 1st MR of Add Geo support for Packages::Nuget::SymbolUplo... (#422929 - closed), in which we modify database schemas to prepare to add Geo support for Packages::Nuget::Symbol.

References

• Add Geo support for Packages::Nuget::SymbolUplo... (#422929 - closed) • Moaz Khalifa • 18.10 • At risk
• https://docs.gitlab.com/development/geo/

Screenshots or screen recordings

N/A

How to set up and validate locally

N/A

MR acceptance checklist

Evaluate this MR against the MR acceptance checklist. It helps you analyze changes to reduce risks in quality, performance, reliability, security, and maintainability.

Related to #566404 (closed)