cmd/cue/cmd: allow lossy conversion by default and add --strict option

Applies to JSON Schema now, but generallly applicable for
other conversions.

Change-Id: Ie6abe0ea0daf2d2ede1850a16cd2c1d831fb7f13
Reviewed-on: https://cue-review.googlesource.com/c/cue/+/5649
Reviewed-by: Marcel van Lohuizen <mpvl@golang.org>
diff --git a/internal/encoding/encoding.go b/internal/encoding/encoding.go
index 5b4a733..e720284 100644
--- a/internal/encoding/encoding.go
+++ b/internal/encoding/encoding.go
@@ -132,6 +132,7 @@
 	PkgName string // package name for files to generate
 
 	Force     bool // overwrite existing files.
+	Strict    bool
 	Stream    bool // will potentially write more than one document per file
 	AllErrors bool
 
@@ -246,6 +247,8 @@
 		cfg := &jsonschema.Config{
 			ID:      id,
 			PkgName: cfg.PkgName,
+
+			Strict: cfg.Strict,
 		}
 		file, err = simplify(jsonschema.Extract(i, cfg))
 		return file, id, err