feat: allow multi-select with SHIFT key in singleClick mode

[andresbono]

Description

This is a follow-up of #2953 to also take into account the SHIFT key for selecting multiple files when singleClick mode is active.

🚨 Before submitting your PR, please indicate which issues are either fixed or closed by this PR. See GitHub Help: Closing issues using keywords.

• DO make sure you are requesting to pull a topic/feature/bugfix branch (right side). Don't request your master!
• DO make sure you are making a pull request against the master branch (left side). Also you should start your branch off our master.
• DO make sure that File Browser can be successfully built. See builds and development.
• AVOID breaking the continuous integration build.

Further comments

n/a