test(browser): Add integration tests for addBreadcrumb.

[onurtemizkan]

Part of: #4333

[github-actions]

size-limit report

Path	Base Size (44e0841)	Current Size	Change
@sentry/browser - CDN Bundle (gzipped)	20.24 KB	20.31 KB	+0.35% 🔺
@sentry/browser - CDN Bundle (minified)	64.29 KB	64.7 KB	+0.65% 🔺
@sentry/browser - Webpack	22.22 KB	22.29 KB	+0.34% 🔺
@sentry/browser - Webpack - gzip = false	75.7 KB	76.23 KB	+0.71% 🔺
@sentry/react - Webpack	22.25 KB	22.33 KB	+0.33% 🔺
@sentry/nextjs Client - Webpack	46.35 KB	46.45 KB	+0.21% 🔺
@sentry/browser + @sentry/tracing - CDN Bundle (gzipped)	28.34 KB	28.45 KB	+0.39% 🔺