use structured images with metainfo (blur placeholder) (#48531)
### What?
add support for blur placeholder generation to turbopack
add `StructuredImageModuleType` which is used with `ModuleType::Custom`
to allow importing an image as `{ url, width, height, blurDataURL,
blurWidth, blurHeight }`
in contrast to next.js with webpack this will also generate blur
placeholder in development instead of using a _next/image reference.
This should lead to more production-like experience (at the cost of a
little bit of compilation time).
turbo PR: https://github.com/vercel/turbo/pull/4621
### Why?
Turbopack was crashing on `placeholder="blur"` before.
fixes WEB-534
### Turbopack changes
* https://github.com/vercel/turbo/pull/4521 <!-- OJ Kwon -
feat(contextcondition): support InPath contextcondition -->
* https://github.com/vercel/turbo/pull/4601 <!-- Alex Kirszenberg -
Chunking Context Refactor pt. 3: Address PR comments from pt. 2 -->
* https://github.com/vercel/turbo/pull/4623 <!-- Tobias Koppers -
exclude turborepo from turbopack bench tests -->
* https://github.com/vercel/turbo/pull/4399 <!-- Leah - support
require.context -->
* https://github.com/vercel/turbo/pull/4610 <!-- OJ Kwon - test(subset):
add mdx test into subset -->
* https://github.com/vercel/turbo/pull/4624 <!-- Tobias Koppers - run
benchmarks on windows and macOS too -->
* https://github.com/vercel/turbo/pull/4620 <!-- Alex Kirszenberg - Make
ContainmentTree fully generic -->
* https://github.com/vercel/turbo/pull/4600 <!-- Tobias Koppers - add
getChunkPath method -->
* https://github.com/vercel/turbo/pull/4621 <!-- Tobias Koppers - add
turbopack-image -->
* https://github.com/vercel/turbo/pull/4639 <!-- Tobias Koppers -
restrict snapshot path for windows path length limit -->
* https://github.com/vercel/turbo/pull/4641 <!-- Tobias Koppers - put
webp behind a feature flag -->
