feat(core): Add ignoreTransactions option

[mydea]

This works similar to ignoreErrors, but matches transaction names.

ref getsentry/develop#884

[github-actions]

size-limit report 📦

Path	Size
@sentry/browser - ES5 CDN Bundle (gzipped + minified)	20.62 KB (+0.21% 🔺)
@sentry/browser - ES5 CDN Bundle (minified)	64.4 KB (+0.32% 🔺)
@sentry/browser - ES6 CDN Bundle (gzipped + minified)	19.17 KB (+0.2% 🔺)
@sentry/browser - ES6 CDN Bundle (minified)	56.78 KB (+0.37% 🔺)
@sentry/browser - Webpack (gzipped + minified)	21.63 KB (+0.18% 🔺)
@sentry/browser - Webpack (minified)	72.04 KB (+0.54% 🔺)
@sentry/react - Webpack (gzipped + minified)	21.65 KB (+0.19% 🔺)
@sentry/nextjs Client - Webpack (gzipped + minified)	51.93 KB (+0.1% 🔺)
@sentry/browser + @sentry/tracing - ES5 CDN Bundle (gzipped + minified)	27.96 KB (+0.12% 🔺)
@sentry/browser + @sentry/tracing - ES6 CDN Bundle (gzipped + minified)	26.14 KB (+0.14% 🔺)
@sentry/replay ES6 CDN Bundle (gzipped + minified)	44.33 KB (0%)
@sentry/replay - Webpack (gzipped + minified)	38.39 KB (0%)
@sentry/browser + @sentry/tracing + @sentry/replay - ES6 CDN Bundle (gzipped + minified)	62.57 KB (+0.05% 🔺)
@sentry/browser + @sentry/replay - ES6 CDN Bundle (gzipped + minified)	56.1 KB (+0.07% 🔺)