feat: [#185575919] change favicon and title based on environment

[seidior]

Description

This introduces per-environment titles and favorites icons, distinct for the following environments:

• prod
• staging
• dev
• content
• testing
• localhost

Ticket

This pull request resolves #185575919.

Code author checklist

• [x] I have rebased this branch from the latest main branch
• [x] I have performed a self-review of my code
• [x] I have created and/or updated relevant documentation on the engineering documentation website
• [x] I have not used any relative imports
• [x] I have pruned any instances of unused code
• [x] I have not added any markdown to labels, titles and button text in config
• [x] If I added/updated any values in userData (including profileData, formationData etc), then I added a new migration file
• [x] I have checked for and removed instances of unused config from CMS
• [x] If I added any new collections to the CMS config, then I updated the search tool and cmsCollections.ts (see CMS Additions in Engineering Reference/FAQ on the engineering documentation site)
• [x] I have updated relevant .env values in both .env-template and in Bitwarden