Default branch names in the Web IDE should include the username

Problem to solve

When creating a new branch from the Web IDE, you are prompted with a default suggested branch name. In the older version of the Web IDE, that default suggestion included your username, which made it easier to find the branch if you navigated away from the Web IDE before creating an MR.

Proposal

Adopt the same default naming convention for new branches in the Web IDE Beta.

Availability and Testing

A quick unit test should be suffice. No need to update any E2E tests.