Fix Git editor reword workflow and UI coverage

- show Git editor file paths instead of the submitted git command
- surface follow-up commit message editors during interactive rebase reword
- add rename-commit UI tests for editor and amend-message solution paths
- add broader embedded level solution scenarios for alternate Git workflows

app/src/main/java/solutions/tretter/githugandroid/levels/RmLevel.kt

@@ -20,5 +20,6 @@ internal fun rmLevel(): Level = level(
     },
     testCases = listOf(
         levelTestCase("git rm deleted path", "git rm deleteme.rb"),
+        levelTestCase("stage deleted path", "git add -u deleteme.rb"),
     ),
 )