Fix PR title generation from branch name to match GitHub.com behavior (#8558)

* Initial plan

* chore: initial plan for branch name to PR title fix

Co-authored-by: alexr00 <38270282+alexr00@users.noreply.github.com>

* fix: replace dashes and underscores with spaces in PR title generated from branch name

Co-authored-by: alexr00 <38270282+alexr00@users.noreply.github.com>

Author: Copilot

src/github/createPRViewProvider.ts

@@ -758,7 +758,8 @@ export class CreatePullRequestViewProvider extends BaseCreatePullRequestViewProv
 
 		const name = compareBranch.name;
 		const branchNameTitle = (name: string) => {
-			return `${name.charAt(0).toUpperCase()}${name.slice(1)}`;
+			const nameWithSpaces = name.replace(/[-_]/g, ' ');
+			return `${nameWithSpaces.charAt(0).toUpperCase()}${nameWithSpaces.slice(1)}`;
 		};
 
 		// If branchName is selected, use the branch name as the title