On Issue, "checkout topic branch" should use existing branch if already created in UI

This is similar to #4120, but not identical.

There is a feature in the UI of the website, in the right side-bar of an issue, under "Development", to create a branch for an issue.

In VS Code PR and Issue view, under "Issues > Recent Issues", when clicking on an issue then the arrow to "Start working on issue and checkout topic branch", my feature requirements are :

• if a branch has already been created for this issue, use this branch instead of creating a new one
• if creating a new branch from here, give the user to rename this branch, and attach it to the issue so that it is visible in the issue side-bar on the github website, under the "Development" section

Comienza en el flujo Issues > Recent Issues de la vista PR and Issue de VS Code y sigue el comando que hay detrás de “Start working on issue and checkout topic branch.” Comprueba cómo se representa la asociación del issue de GitHub con el branch de Development. Se considera terminado cuando se reutiliza un branch existente del issue, mientras que un branch recién creado puede renombrarse y asociarse al issue para que se muestre en GitHub.