Fix Passive Tree Management Titles

[pHiney]

Fixes #3961.

Description of the problem being solved:

When Managing Passive Trees (Copy, Rename, New, Delete). The title of the popups are sometimes incorrect.

Steps taken to verify a working solution:

• on Tree tab, choose "Manage Trees ..."
• Choose a Passive Tree and select Copy, Rename, New, and Delete and confirm the titles match the action
• Changed "Delete Spec" to "Delete Tree" as Spec is an internal name.

The alternative was to set Copy, Rename, and New to "Set Name" for consistency.

Link to a build that showcases this PR:

N/A

Before screenshot:

After screenshot: