Landscape Sketchbook - "Thrones" of Eldraine unusable

**Describe the bug**
Due to a typo, the Landscape Sketchbook intended to allow use of lands from _Throne_ of Eldraine instead attempts to lead lands from _Thrones_ of Eldraine, which does not exist, and therefore does nothing.

**To Reproduce**
Steps to reproduce the behavior:
1. Enter Adventure mode
2. Enter `give item "Landscape Sketchbook - Thrones of Eldraine"` in the console
3. Edit your current deck
4. Select "Add Basic Lands" from the ... menu
5. Observe that "Throne of Eldraine (ELD)" is not present in the list of sets to choose from

**Expected behavior**
The item should allow adding basic lands from Throne of Eldraine (ELD) to the deck

**Desktop (please complete the following information):**
- OS: Windows
- Version v.2.0.14-SNAPSHOT-07.20

**Additional context**
The item should be renamed to "Landscape Sketchbook - Throne of Eldraine" to match the official set name and allow loading the correct set

Search the repository for the exact item name "Landscape Sketchbook - Thrones of Eldraine" and trace how its set code is loaded. Rename the item to use the singular official set name, then reproduce the Adventure mode steps and confirm that Throne of Eldraine (ELD) appears under Add Basic Lands.

Written by the indexing model from the issue text.