give `corpus-view.ts` an interlock to warn about gitcasso running

[nedtwigg]

• when testing gitcasso using pnpm corpus
• if you have the gitcasso extension installed in your browser (dev or prod, doesn't matter)
• then you will get extremely misleading results
• right now we warn in the docs

• gitcasso/CONTRIBUTING.md

  Lines 89 to 91 in 45ea112

  	### Viewing corpus
  	- **DISABLE GITCASSO IN YOUR BROWSER!!**

• it would be much better if we could somehow detect that the browser extension was running, and give a big fat warning if that is the case
  • maybe if content.ts runs on localhost we add some header into the DOM
  • and then corpus-view.ts has some js that looks for that and makes a big warning div
  • then we can remove the warning in CONTRIBUTING.md
• I have already lost hours to this mistake, new contributors are guaranteed to lose more

[cavia-porcellus]

Make a comment so I can edit it later.