Migrate Version URL Parser to TypeScript

[Manik-Khajuria-5]

Summary

Fixes : #3761
This PR migrates the version URL parsing logic to TypeScript as part of the ongoing TS conversion effort.

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Changes Made

• Migrated parseUrlParams and helpers to TypeScript
• Added explicit types for:
  • validateVersion(version: string | null)
  • validateBool(value: string | null, defaultValue: boolean)
  • getNewestVersion(versions: string[])
• Introduced an exported interface for parsed URL params
• Normalized p5Versions to handle both string and { version, label } entries safely
• Migrated existing tests to TypeScript with no behavior changes

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Related Issue

Closes #3761

I have verified that this pull request:

• has no linting errors (npm run lint)
• has no test errors (npm run test)
• has no typecheck errors (npm run typecheck)
• is from a uniquely-named feature branch and is up to date with the develop branch.
• is descriptively named and links to an issue number, i.e. Fixes #3761
• meets the standards outlined in the accessibility guidelines

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