add support for excludes in input dir

This adds support for `--include` and `--exclude` for directory inputs.

For instance, this is what you would want to use when passing dagger
repository as an input:

```
inputs:
    repository:
        dir:
            path: .
            exclude:
                - '**/node_modules'
                - cmd/dagger/dagger
                - cmd/dagger/dagger-debug
```

Signed-off-by: Andrea Luzzardi <aluzzardi@gmail.com>

stdlib/dagger/op/op.cue

@@ -36,6 +36,7 @@ package op
 	do:  "local"
 	dir: string
 	include: [...string]
+	exclude: [...string]
 }
 
 // FIXME: bring back load (more efficient than copy)