[Replay] Post-Migration Improvements

[Lms24]

Problem Statement

With #5326 completed and both, NPM package and CDN bundles released, we can conclude the initial migration phase of the Replay integration into the monorepo. This doesn't mean though, that we're done. There are still a lot of improvements we should address sooner or later.

Progress

• [Replay] Allow using replay without installing @sentry/replay #6326
• [Replay] Make replay sample rates top-level config #6351
• Add Basic Replay Integration documentation sentry-docs#5894
• [meta] Move issues to this repo
• [Replay] Upstream replay event sending #6480
• [replay] Linting & code quality alignments #6323