feat(Provenance): Add a LocalProvenance sub interface

In contrast to the previously added `RemoteProvenance` stands the
`LocalProvenance`, which has no remote source, but instead references
a local input of some kind.

See [1] for more context on the new Provenance Hierarchy.

[1]: oss-review-toolkit#8803 (comment)

Signed-off-by: Jens Keim <jens.keim@forvia.com>

model/src/main/kotlin/Provenance.kt

@@ -19,6 +19,8 @@
 
 package org.ossreviewtoolkit.model
 
+import java.nio.file.Files
+import java.nio.file.Path
 import com.fasterxml.jackson.core.JsonParser
 import com.fasterxml.jackson.databind.DeserializationContext
 import com.fasterxml.jackson.databind.JsonNode
@@ -45,6 +47,8 @@ sealed interface KnownProvenance : Provenance
 
 sealed interface RemoteProvenance : KnownProvenance
 
+sealed interface LocalProvenance : KnownProvenance
+
 /**
  * Provenance information for a source artifact.
  */