ref(transports): Add back client reports

[lforst]

This PR mainly aims to add back client reports to the SDK using the new transports:

Contents

• Make transport.send() return void instead of response information. We do not need that information.
• Clean up transport types
  • Introduce DropReason type to use in place of Outcome to be more in line with our docs. Outcome is a very overloaded term. Outcome now describes an "outcome object" like the docs use the term:
  • Remove Response, EventStatus, SentryRequestType, SentryRequest types - were not needed anymore
  • Introduce DataCategory type in favor of TransportCategory to be more in line with the docs. We use it for client outcome categories and rate limit categories.
  • Introduce an EnvelopeItemType type.
• Introduce function envelopeItemTypeToDataCategory to map from envelope item types to data categories. This mapping is taken from the python SDK.
• Remove eventStatusFromHttpCode function. It is not needed anymore.
• Add functionality to BaseClient to track dropped events
• Send client reports in sdks

[github-actions]

size-limit report 📦

Path	Size
@sentry/browser - ES5 CDN Bundle (gzipped + minified)	18.45 KB (-8.4% 🔽)
@sentry/browser - ES5 CDN Bundle (minified)	57.8 KB (-10.54% 🔽)
@sentry/browser - ES6 CDN Bundle (gzipped + minified)	17.2 KB (-8.81% 🔽)
@sentry/browser - ES6 CDN Bundle (minified)	51.97 KB (-10.35% 🔽)
@sentry/browser - Webpack (gzipped + minified)	21.06 KB (-9.38% 🔽)
@sentry/browser - Webpack (minified)	72.94 KB (-10.74% 🔽)
@sentry/react - Webpack (gzipped + minified)	21.09 KB (-9.4% 🔽)
@sentry/nextjs Client - Webpack (gzipped + minified)	46.07 KB (-4.13% 🔽)
@sentry/browser + @sentry/tracing - ES5 CDN Bundle (gzipped + minified)	24.22 KB (-7.12% 🔽)
@sentry/browser + @sentry/tracing - ES6 CDN Bundle (gzipped + minified)	22.72 KB (-7.19% 🔽)