[Feature Request] Library Manager: Allow selecting multiple libraries to update

Updating libraries one by one can be tedious if you have a large set of libraries to update at any time. Please provide a way to have the software iterate over all or a set of them to do the update, instead of having to select each one of them and deal with laggy UI.

Start by locating the Arduino IDE 1.x Library Manager and the existing single-library update flow. Trace how library selection and update progress are handled, then define completion as allowing all or a selected set of libraries to update without requiring individual selection; no specific files or tests are identified in the issue.

Written by the indexing model from the issue text.