fix: nested stylesheets should have absolute URLs (#1533)

* Replace relative URLs with absolute URLs when stringifying stylesheets

* Add test to show desired behavior for imported stylesheets from seperate directory

* Rename `absoluteToStylesheet` to `absolutifyURLs` and call it once after stringifying imported stylesheet

* Don't create the intermediary array of the spread operator

* Formalize that `stringifyRule` should expect a sheet href

* Ensure a <style> element can also import and gets it's url absolutized

* Handle case where non imported stylesheet has relative urls that need to be absolutified

* Clarify in test files where jpegs are expected to appear in absolutified urls

* Move absolutifyURLs call for import rules out of trycatch

* Add a benchmarking test for stringifyStylesheet

* Avoid the duplication on how to fall back

---------

Co-authored-by: Eoghan Murray <eoghan@getthere.ie>
Co-authored-by: eoghanmurray <eoghanmurray@users.noreply.github.com>

packages/rrweb-snapshot/package.json

@@ -10,6 +10,7 @@
     "test:watch": "vitest watch",
     "retest:update": "vitest run --update",
     "test:update": "yarn build && vitest run --update",
+    "bench": "vite build && vitest bench",
     "dev": "vite build --watch",
     "build": "yarn turbo prepublish -F rrweb-snapshot",
     "check-types": "tsc --noEmit",