Improve layering for git model (#272857)

* Improve layering for git model
- Git clone doesn't belong in the model, removed it
- All the extra repo picking didn't seem to fit into `Git` though, as that is really about git operations
- Added a `CloneUtils` namespace for all the clone stuff to live.

* Update extensions/git/src/clone.ts

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

* CloneManager class

* public/private

extensions/git/src/commands.ts

@@ -19,6 +19,7 @@ import { GitTimelineItem } from './timelineProvider';
 import { ApiRepository } from './api/api1';
 import { getRemoteSourceActions, pickRemoteSource } from './remoteSource';
 import { RemoteSourceAction } from './typings/git-base';
+import { CloneManager } from './cloneManager';
 
 abstract class CheckoutCommandItem implements QuickPickItem {
 	abstract get label(): string;
@@ -774,7 +775,8 @@ export class CommandCenter {
 		private model: Model,
 		private globalState: Memento,
 		private logger: LogOutputChannel,
-		private telemetryReporter: TelemetryReporter
+		private telemetryReporter: TelemetryReporter,
+		private cloneManager: CloneManager
 	) {
 		this.disposables = Commands.map(({ commandId, key, method, options }) => {
 			const command = this.createCommand(commandId, key, method, options);
@@ -1016,12 +1018,12 @@ export class CommandCenter {
 
 	@command('git.clone')
 	async clone(url?: string, parentPath?: string, options?: { ref?: string }): Promise<void> {
-		await this.model.clone(url, { parentPath, ...options });
+		await this.cloneManager.clone(url, { parentPath, ...options });
 	}
 
 	@command('git.cloneRecursive')
 	async cloneRecursive(url?: string, parentPath?: string): Promise<void> {
-		await this.model.clone(url, { parentPath, recursive: true });
+		await this.cloneManager.clone(url, { parentPath, recursive: true });
 	}
 
 	@command('git.init')