Add Swift package registry (#22404)

This PR adds a [Swift](https://www.swift.org/) package registry.


![grafik](https://user-images.githubusercontent.com/1666336/211842523-07521cbd-8fb6-400f-820c-ee8048b05ae8.png)

models/packages/descriptor.go

@@ -24,6 +24,7 @@ import (
 	"code.gitea.io/gitea/modules/packages/pub"
 	"code.gitea.io/gitea/modules/packages/pypi"
 	"code.gitea.io/gitea/modules/packages/rubygems"
+	"code.gitea.io/gitea/modules/packages/swift"
 	"code.gitea.io/gitea/modules/packages/vagrant"
 
 	"github.com/hashicorp/go-version"
@@ -159,6 +160,8 @@ func GetPackageDescriptor(ctx context.Context, pv *PackageVersion) (*PackageDesc
 		metadata = &pypi.Metadata{}
 	case TypeRubyGems:
 		metadata = &rubygems.Metadata{}
+	case TypeSwift:
+		metadata = &swift.Metadata{}
 	case TypeVagrant:
 		metadata = &vagrant.Metadata{}
 	default:

models/packages/package.go

@@ -44,6 +44,7 @@ const (
 	TypePub       Type = "pub"
 	TypePyPI      Type = "pypi"
 	TypeRubyGems  Type = "rubygems"
+	TypeSwift     Type = "swift"
 	TypeVagrant   Type = "vagrant"
 )
 
@@ -62,6 +63,7 @@ var TypeList = []Type{
 	TypePub,
 	TypePyPI,
 	TypeRubyGems,
+	TypeSwift,
 	TypeVagrant,
 }
 
@@ -96,6 +98,8 @@ func (pt Type) Name() string {
 		return "PyPI"
 	case TypeRubyGems:
 		return "RubyGems"
+	case TypeSwift:
+		return "Swift"
 	case TypeVagrant:
 		return "Vagrant"
 	}
@@ -133,6 +137,8 @@ func (pt Type) SVGName() string {
 		return "gitea-python"
 	case TypeRubyGems:
 		return "gitea-rubygems"
+	case TypeSwift:
+		return "gitea-swift"
 	case TypeVagrant:
 		return "gitea-vagrant"
 	}