Add ability to prevent config.json being written to `~/Documents/hugg…

…ingface/...` (#262)

* `fetchAvailableModels` and `fetchAvailableModels` take `downloadBase: URL?` param

Which controls where HubAPI leaves the config.json that it downloads.

* `recommendedRemoteModels` also gets passed the downloadBase (and repo param)

Sources/WhisperKit/Core/WhisperKit.swift

@@ -152,14 +152,14 @@ open class WhisperKit {
         return modelSupport(for: deviceName)
     }
 
-    public static func recommendedRemoteModels(from repo: String = "argmaxinc/whisperkit-coreml") async -> ModelSupport {
+    public static func recommendedRemoteModels(from repo: String = "argmaxinc/whisperkit-coreml", downloadBase: URL? = nil) async -> ModelSupport {
         let deviceName = Self.deviceName()
-        let config = await Self.fetchModelSupportConfig(from: repo)
+        let config = await Self.fetchModelSupportConfig(from: repo, downloadBase: downloadBase)
         return modelSupport(for: deviceName, from: config)
     }
 
-    public static func fetchModelSupportConfig(from repo: String = "argmaxinc/whisperkit-coreml") async -> ModelSupportConfig {
-        let hubApi = HubApi()
+    public static func fetchModelSupportConfig(from repo: String = "argmaxinc/whisperkit-coreml", downloadBase: URL? = nil) async -> ModelSupportConfig {
+        let hubApi = HubApi(downloadBase: downloadBase)
         var modelSupportConfig = Constants.fallbackModelSupportConfig
 
         do {
@@ -176,8 +176,8 @@ open class WhisperKit {
         return modelSupportConfig
     }
 
-    public static func fetchAvailableModels(from repo: String = "argmaxinc/whisperkit-coreml", matching: [String] = ["*"]) async throws -> [String] {
-        let modelSupportConfig = await fetchModelSupportConfig(from: repo)
+    public static func fetchAvailableModels(from repo: String = "argmaxinc/whisperkit-coreml", matching: [String] = ["*"], downloadBase: URL? = nil) async throws -> [String] {
+        let modelSupportConfig = await fetchModelSupportConfig(from: repo, downloadBase: downloadBase)
         let supportedModels = modelSupportConfig.modelSupport().supported
         var filteredSupportSet: Set<String> = []
         for glob in matching {
@@ -290,10 +290,10 @@ open class WhisperKit {
             self.modelFolder = URL(fileURLWithPath: folder)
         } else if download {
             // Determine the model variant to use
-            let modelSupport = await WhisperKit.recommendedRemoteModels()
+            let repo = modelRepo ?? "argmaxinc/whisperkit-coreml"
+            let modelSupport = await WhisperKit.recommendedRemoteModels(from: repo, downloadBase: downloadBase)
             let modelVariant = model ?? modelSupport.default
 
-            let repo = modelRepo ?? "argmaxinc/whisperkit-coreml"
             do {
                 self.modelFolder = try await Self.download(
                     variant: modelVariant,