Add setting for public url

[ogenstad]

This PR just renames a setting that was previously used for local development because Infrahub would be exposed on a different port compared to the frontend app. It turns out that it can be required for SSO depending on how the infrastructure is configured and accessed. The PR only promotes a development setting and makes it public.

Fixes #5306

[codspeed-hq]

CodSpeed Performance Report

Merging #5404 will improve performances by 35.14%

_{Comparing pog-public-url-IFC-1029 (fd8102a) with stable (929df94)}

Summary

⚡ 1 improvements
✅ 9 untouched benchmarks

Benchmarks breakdown

	Benchmark	stable	pog-public-url-IFC-1029	Change
⚡	test_schemabranch_duplicate	443.6 µs	328.3 µs	+35.14%

[lykinsbd]

Looks good 👍🏻