fix default path bug related to branch prefix (microsoft#258709)

* fix default path bug related to branch prefix

* remove branch prefix first, then get last component

* replace / with -

* clean up

Author: nguyenchristy

extensions/git/src/commands.ts

@@ -3455,10 +3455,9 @@ export class CommandCenter {
 			commitish = choice.refName;
 		}
 
-
-		const worktreeName = (branch ?? commitish).startsWith(branchPrefix)
-			? (branch ?? commitish).substring(branchPrefix.length)
-			: (branch ?? commitish);
+		const worktreeName = ((branch ?? commitish).startsWith(branchPrefix)
+			? (branch ?? commitish).substring(branchPrefix.length).replace(/\//g, '-')
+			: (branch ?? commitish).replace(/\//g, '-'));
 
 		// If user selects folder button, they manually select the worktree path through folder picker
 		const getWorktreePath = async (): Promise<string | undefined> => {