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/BranchLevel.kt

@@ -17,5 +17,6 @@ internal fun branchLevel(): Level = level(
     validator = repoPredicate { repo -> "test_code" in repo.branches && repo.headBranch == "master" },
     testCases = listOf(
         levelTestCase("create branch", "git branch test_code"),
+        levelTestCase("create branch from master", "git branch test_code master"),
     ),
 )