Create wide-format metadata with ease

Create a system where a blueprint can generate wide-format metadata based on input long-form datasets. Should be easily configurable, like:

```r
blueprint(
  # ...
  meta_wider = TRUE,
  meta_pattern = "(.*)_(.*)"
)
```

similar to the [`tidyr::pivot_longer()`](https://tidyr.tidyverse.org/reference/pivot_longer.html) syntax to identify which columns come from where.