Sentry Astro SDK

[Lms24]

Problem Statement

We're going to build an SDK for Astro! This is necessary to make Spotlight work properly with Astro and it will make Sentry compatible to be used within Astro projects.

Solution Brainstorm

The details remain TBD as we work through things but here's a rough outline of the necessary tasks:

### Initial Tasks
- [ ] https://github.com/getsentry/sentry-javascript/pull/9187
- [ ] https://github.com/getsentry/sentry-javascript/pull/9218
- [ ] https://github.com/getsentry/sentry-javascript/pull/9193
- [x] Figure out necessary build settings
- [x] Add support for `Sentry.init` config files for client and server
- [x] Add Vite plugin for source map upload in the integration
- [x] Make sure, package structure and content adheres to Astro Integration specification

As for publishing, we will publish the SDK as alpha/beta first, leaving us a bit of headroom to change public API if necessary and eventually promote it to stable.

### Adding Astro as a Sentry Platform
- [ ] https://github.com/getsentry/platformicons/pull/111
- [ ] https://github.com/getsentry/sentry/pull/58158
- [ ] https://github.com/getsentry/sentry/pull/58151
- [ ] https://github.com/getsentry/sentry/pull/58156
- [ ] https://github.com/getsentry/sentry-release-registry/pull/128
- [ ] https://github.com/getsentry/sentry-docs/pull/8267
- [ ] https://github.com/getsentry/sentry/pull/58435
- [ ] https://github.com/getsentry/static-sites/pull/2005

Stretch Goals / open ends

If we have time/feel it's necessary or nice to have for an SDK:

• Add a setup wizard for Astro
• Add other Astro-specific features
• Do we need a routing instrumentation?
• Support non-Node runtimes?

How to deal with other UI frameworks?

Given that Astro supports building UIs with a number of frontend frameworks (React, Svelte, Vue, etc), we might want to consider adding our respective UI framework SDKs to the project. However, I'd argue that this only makes sense in islands. For them, we can direct users in docs to use the respective Sentry SDK to unlock framework-specifc features. For example, component tracking or error handlers/boundaries. (Great timing: We just decoupled SDK intialization and Vue-specific instrumentation in #9180)

[AbhiPrasad]

See #7378