Build: Add .next/trace-build with high level trace (#83949)
## What?
- Adds a new file `.next/trace-build` with a high level overview of the
build process. This is an extra file next to `.next/trace`.
`.next/trace` includes a lower level trace when using webpack.
`.next/trace-build` is the same between webpack/Turbopack in terms of
spans emitted (though `run-turbopack` vs `run-webpack` span).
Included trace spans are:
```
'next-build',
'run-turbopack',
'run-webpack',
'run-typescript',
'run-eslint',
'static-check',
'static-generation',
'output-export-full-static-export',
```
`run-turbopack` is only included when Turbopack is used. `run-webpack`
when webpack is used.
`run-typescript` and `run-eslint` are concurrent.
`output-export-full-static-export` is only included when using `output:
'export'`.
