Create new branch from branch selection dropdown (#2130)

* Create new branch from branch selection dropdown and rewrite it to VueJS

* Make updateLocalCopyToCommit as not exported

* Move branch name validation to model

* Fix possible race condition

public/less/_base.less

@@ -329,6 +329,10 @@ pre, code {
 			background-color: #a1882b !important;
 		}
 	}
+
+	.branch-tag-choice {
+		line-height: 20px;
+	}
 }