feat(transcations) Transaction source

[smeubank]

Problem Statement

Add the source of a transaction name to all events sent with the SDK.
See https://develop.sentry.dev/sdk/event-payloads/transaction/#transaction-annotations

To do:

Integrations where we have to check/add transaction source:

• asgi (on event, in event processor, has code for saving url style transaction names, but can this only if fastapi is used...)
• flask (on scope, outside event processor)
• django (on scope, outside event processor and multiple other places, TODO later: test for "/message/:id" names)
• bottle (on event, in event processor)
• falcon (on event, in event processor, TODO: there is no endpoint transaction_style (create ticket for later?))
• pyramid (on scope, outside event processor)
• quart (on scope, outside event processor)
• sanic
• celery (TODO: update TESTS! rest is done)
• wsgi (does not set transaction names (or sources) what I think should also be that way in ASGI...)
• spark (does not have transactions)
• tornado (on event, in event processor)
• trytond (does not have transactions)
• aiohttp (on scope, outside event processor)
• starlette (needs to use transaction_from_function() to have better endpoint names)
• aws_lambda (need to check tests in CI because did not run locally because I am too lazy to setup env vars to actual AWS to run tests.)
• gcp
• chalice (on scope, outside event processor)

Reference

Develop Spec: Transaction Annotations

getsentry/sentry-javascript#5367

getsentry/sentry-javascript#5345

getsentry/relay#1330

getsentry/develop#624