H-3044: Improve ontology type id typings

[CiaranMn]

🌟 What is the purpose of this PR?

This PR is spun out of work I'm doing on improving entity property updates, and improves the typing of our generated "ontology type ids" objects by correctly branding the property base URLs as BaseUrl, removing the need to extract or assert them as being such everywhere.

🔍 What does this change?

• Brand base URLs in the generated ids
• Remove extractBaseUrl and as BaseUrl where we need to use those base urls

Pre-Merge Checklist 🚀

🚢 Has this modified a publishable library?

This PR:

• [x] does not modify any publishable blocks or libraries, or modifications do not need publishing

📜 Does this require a change to the docs?

The changes in this PR:

• [x] are internal and do not require a docs change

🕸️ Does this require a change to the Turbo Graph?

The changes in this PR:

• [x] do not affect the execution graph

🛡 What tests cover this?

• tsc