Select multiple notes for bulk action - i.e. tagging, trashing several notes at once

### What

The ability to select more than one note in the side bar navigation pane. Ideally using 'Shift-click' or check boxes.

### Why

This will allow the ability to reorganize notes, for example apply a tag to multiple notes at once, trash multiple notes at once etc.
This is especially a necessary for new adopters, wishing to import notes from other platforms. After the import re-organization is needed, and with a large library of notes it is not a small task if notes need to be modified/tagged individually.

For someone like myself, having hundreds of notes, re-organizing individual notes, one at a time, would take hours. There are times when I need to trash or re tag multiple notes due to change in work/study etc. Having to do this one at a time is not an option.

### How

Start by locating the sidebar navigation and the existing single-note tagging and trash actions. Define how multi-selection should work, including Shift-click or checkboxes, then verify that selected notes can be reorganized, tagged, and trashed together.

Written by the indexing model from the issue text.