Support use of custom app root with system config in CLI commands (#1600)

## Type of Change
- [x] Bug fix

## Motivation and Context
Many CLI commands need to reference the system configurations for
`container`. Previously, CLI commands would try to load the system
configurations from the default application root location, regardless of
if `container` had been started with a custom application root location.
This PR fixes that issue by having each CLI command ping the APIServer's
health check service to get the correct app root path.

Closes https://github.com/apple/container/issues/1576

## Testing
- [x] Tested locally

Signed-off-by: Kathryn Baldauf <k_baldauf@apple.com>

Sources/ContainerCommands/Image/ImageDelete.swift

@@ -109,7 +109,7 @@ extension Application {
         }
 
         public mutating func run() async throws {
-            let containerSystemConfig: ContainerSystemConfig = try await ConfigurationLoader.load()
+            let containerSystemConfig: ContainerSystemConfig = try await Application.loadContainerSystemConfig()
             try await DeleteImageImplementation.removeImage(options: options, containerSystemConfig: containerSystemConfig, log: log)
         }
     }

Sources/ContainerCommands/Image/ImageInspect.swift

@@ -36,7 +36,7 @@ extension Application {
         public init() {}
 
         public func run() async throws {
-            let containerSystemConfig: ContainerSystemConfig = try await ConfigurationLoader.load()
+            let containerSystemConfig: ContainerSystemConfig = try await Application.loadContainerSystemConfig()
             let uniqueNames = Set(images)
             let result = try await ClientImage.get(
                 names: Array(uniqueNames), containerSystemConfig: containerSystemConfig

Sources/ContainerCommands/Image/ImageList.swift

@@ -45,7 +45,7 @@ extension Application {
         public var logOptions: Flags.Logging
 
         public mutating func run() async throws {
-            let containerSystemConfig: ContainerSystemConfig = try await ConfigurationLoader.load()
+            let containerSystemConfig: ContainerSystemConfig = try await Application.loadContainerSystemConfig()
             try Self.validate(quiet: quiet, verbose: verbose)
 
             var images = try await ClientImage.list().filter { img in

Sources/ContainerCommands/Image/ImagePull.swift

@@ -69,7 +69,7 @@ extension Application {
         }
 
         public func run() async throws {
-            let containerSystemConfig: ContainerSystemConfig = try await ConfigurationLoader.load()
+            let containerSystemConfig: ContainerSystemConfig = try await Application.loadContainerSystemConfig()
             let p = try DefaultPlatform.resolve(platform: platform, os: os, arch: arch, log: log)
 
             let scheme = try RequestScheme(registry.scheme)

Sources/ContainerCommands/Image/ImagePush.swift

@@ -57,7 +57,7 @@ extension Application {
         public init() {}
 
         public func run() async throws {
-            let containerSystemConfig: ContainerSystemConfig = try await ConfigurationLoader.load()
+            let containerSystemConfig: ContainerSystemConfig = try await Application.loadContainerSystemConfig()
             let p = try DefaultPlatform.resolve(platform: platform, os: os, arch: arch, log: log)
 
             let scheme = try RequestScheme(registry.scheme)

Sources/ContainerCommands/Image/ImageSave.swift

@@ -67,7 +67,7 @@ extension Application {
         @Argument var references: [String]
 
         public func run() async throws {
-            let containerSystemConfig: ContainerSystemConfig = try await ConfigurationLoader.load()
+            let containerSystemConfig: ContainerSystemConfig = try await Application.loadContainerSystemConfig()
             let p = try DefaultPlatform.resolve(platform: platform, os: os, arch: arch, log: log)
 
             let progressConfig = try ProgressConfig(

Sources/ContainerCommands/Image/ImageTag.swift

@@ -36,7 +36,7 @@ extension Application {
         public var logOptions: Flags.Logging
 
         public func run() async throws {
-            let containerSystemConfig: ContainerSystemConfig = try await ConfigurationLoader.load()
+            let containerSystemConfig: ContainerSystemConfig = try await Application.loadContainerSystemConfig()
             let existing = try await ClientImage.get(reference: source, containerSystemConfig: containerSystemConfig)
             let targetReference = try ClientImage.normalizeReference(target, containerSystemConfig: containerSystemConfig)
             try await existing.tag(new: targetReference)