ContainerRegistry: Rename other RegistryClient extensions consistently

Author: euanh

Sources/ContainerRegistry/CheckAPI.swift renamed to Sources/ContainerRegistry/RegistryClient+CheckAPI.swift

@@ -12,13 +12,13 @@
 //
 //===----------------------------------------------------------------------===//
 
-import Foundation
+import struct Foundation.URL
 
-public extension RegistryClient {
+extension RegistryClient {
     /// Checks whether the registry supports v2 of the distribution specification.
     /// - Returns: an `true` if the registry supports the distribution specification.
     /// - Throws: if the registry does not support the distribution specification.
-    static func checkAPI(client: HTTPClient, registryURL: URL) async throws -> AuthChallenge {
+    public static func checkAPI(client: HTTPClient, registryURL: URL) async throws -> AuthChallenge {
         // See https://github.com/opencontainers/distribution-spec/blob/main/spec.md#determining-support
 
         // The registry indicates that it supports the v2 protocol by returning a 200 OK response.

Sources/ContainerRegistry/Tags.swift renamed to Sources/ContainerRegistry/RegistryClient+Tags.swift

@@ -12,8 +12,14 @@
 //
 //===----------------------------------------------------------------------===//
 
-public extension RegistryClient {
-    func getTags(repository: ImageReference.Repository) async throws -> Tags {
+extension RegistryClient {
+    /// Fetches all tags defined on a particular repository.
+    ///
+    /// - Parameters:
+    ///   - repository: Name of the repository to list.
+    /// - Returns: a list of tags.
+    /// - Throws: If the tag request fails or the response cannot be decoded.
+    public func getTags(repository: ImageReference.Repository) async throws -> Tags {
         // See https://github.com/opencontainers/distribution-spec/blob/main/spec.md#listing-tags
         let (data, _) = try await executeRequestThrowing(
             .get(repository, path: "tags/list"),