[Scenario Editor] Prohibit the positioning of the ultimate artifact near an edge of the adventure map with the 9 squares rule of the original game

[LeHerosInconnu]

Preliminary checks

• [X] I've checked that there aren't other open issues on the same topic.
• [X] I've checked that this issue is reproducible on the latest snapshot build.

Platform

Windows

Describe the bug

In fheroes2, positioning the ultimate artifact near an edge of the adventure map should not be allowed.

In original game:

In fheroes2:

Also, it shouldn't be possible to save a scenario if there isn't a location available where to automatically place the ultimate artifact (in case the scenario creator doesn't manually position the ultimate artifact). A message should be displayed to indicate this to the scenario creator.

Save file

Here is the test scenario file: Ultitop.zip

Additional info

Related closed issues: https://github.com/ihhub/fheroes2/issues/1944, https://github.com/ihhub/fheroes2/issues/1536.