ref(build): Add central build directory to packages without CDN bundles (Part 1)

[Lms24]

Background

This PR is the continuation of our ongoing effort of introducing a central build directory in all* our packages. In the last PR (#4838), the build directory was added to packages with CDN bundles.

*some packages will not be adjusted, as their build process differs significantly from our other packages (e.g. Ember, Angular soon).

Changes

This PR is part 1 of adding the build directory to packages without CDN bundles. It is split into two parts to make reviewing easier. It covers the following packages:

• Core
• Gatsby
• Hub
• Minimal

Additionally, it adjusts prepack.ts to handle both kinds of packages (with/without CDN bundles) via a CL argument. For the Gatsby SDK, additional actions have to be performed which are only relevant for this package. Therefore, prepack.ts now supports calling a package-specific prepack.ts file located in <package>/scripts/prepack.ts.

While the tarball structure is identical to the structure in #4838 (except for temporary CDN bundles), the build directory structure is simplified due to the fact that there are no CDN bundles or legacy NPM packages to be added to it. Therefore we can reduce one hierarchy level, resulting in the following structure:

<sdk>/
├─ build/
│ ├─ cjs/ // dist until v7
│ │ ├─ CJS modules (+maps)
│ ├─ esm/
│ │ ├─ ES6 modules (+maps)
│ ├─ types/
│ │ ├─ *.d.ts files (+maps)
│ ├─ package.json
│ ├─ LICENSE
│ ├─ README.md
├─ ...

[github-actions]

size-limit report 📦

Path	Size
@sentry/browser - ES5 CDN Bundle (gzipped + minified)	20.24 KB (+0.14% 🔺)
@sentry/browser - ES5 CDN Bundle (minified)	65.17 KB (-0.14% 🔽)
@sentry/browser - ES6 CDN Bundle (gzipped + minified)	18.89 KB (+0.03% 🔺)
@sentry/browser - ES6 CDN Bundle (minified)	58.15 KB (-0.21% 🔽)
@sentry/browser - Webpack (gzipped + minified)	23.25 KB (+0.1% 🔺)
@sentry/browser - Webpack (minified)	82.13 KB (-0.06% 🔽)
@sentry/react - Webpack (gzipped + minified)	23.29 KB (+0.1% 🔺)
@sentry/nextjs Client - Webpack (gzipped + minified)	48.06 KB (+0.08% 🔺)
@sentry/browser + @sentry/tracing - ES5 CDN Bundle (gzipped + minified)	26.17 KB (+0.09% 🔺)
@sentry/browser + @sentry/tracing - ES6 CDN Bundle (gzipped + minified)	24.52 KB (+0.08% 🔺)

[AbhiPrasad]

some small nits but I think we are good!

[Lms24]

Thanks for the review, I added the suggestions