Add --replace option to podman artifact add command

This commit implements the --replace functionality for the artifact add command,
allowing users to replace existing artifacts without having to manually remove
them first.

Changes made:
- Add Replace field to ArtifactAddOptions entity types
- Add --replace CLI flag with validation to prevent conflicts with --append
- Implement replace logic in ABI backend to remove existing artifacts before adding
- Update API handlers and tunnel implementation for podman-remote support
- Add comprehensive documentation and examples to man page
- Add e2e and system BATS tests for --replace functionality
- Fix code formatting in pkg/bindings/artifacts/types_pull_options.go:
  * Reorder imports with proper spacing
  * Fix function declaration spacing
  * Convert spaces to proper tab indentation
  * Remove extraneous blank lines

The --replace option follows the same pattern as other podman replace options
like 'podman container create --replace' and 'podman pod create --replace'.
It gracefully handles cases where no existing artifact exists (no error thrown).

Usage examples:
  podman artifact add --replace quay.io/myimage/artifact:latest /path/to/file
  podman artifact add --replace localhost/test/artifact /tmp/newfile.txt

Fixes: Implements requested --replace functionality for artifact add command
Signed-off-by: Daniel J Walsh <dwalsh@redhat.com>

pkg/api/handlers/libpod/artifacts.go

@@ -223,6 +223,7 @@ func AddArtifact(w http.ResponseWriter, r *http.Request) {
 		Annotations      []string `schema:"annotations"`
 		ArtifactMIMEType string   `schema:"artifactMIMEType"`
 		Append           bool     `schema:"append"`
+		Replace          bool     `schema:"replace"`
 	}{}
 
 	if err := decoder.Decode(&query, r.URL.Query()); err != nil {
@@ -246,6 +247,7 @@ func AddArtifact(w http.ResponseWriter, r *http.Request) {
 		Annotations:      annotations,
 		ArtifactMIMEType: query.ArtifactMIMEType,
 		FileMIMEType:     query.FileMIMEType,
+		Replace:          query.Replace,
 	}
 
 	artifactBlobs := []entities.ArtifactBlob{{