[REQ] Allow Ctrl-Click to Multi-Select from Tree View

[MikeGahrns]

A lot of times I want to do an operation on multiple items in a tree view.

For example, I will go to Genres in the tree list, and want to select “Rock” and “Classic Rock”

In windows (like file selection in Explorer), this is typically done while holding ctrl key down while selecting and clicking on what you want to select. (shift+click to select a contiguous block)

In MMW I can only select one item at a time.

In MMA this works as expected and I can select multiple genres, artists, etc. This is very helpful in quickly creating a now playing queue on the fly.

Note: If column filter is enabled and the tree node is in the filter, then it will need to be updated with the selected nodes.
e.g. Multi Click on Genre, Rock and Classic Rock. If Genre is in the column filter, then Rock and Classic Rock should be selected in the column filter