[Refactorings] Add cursor refactorings for the start of the range

When a range is a single expression/statement/decl or part of
expression, also return cursor based refactorings for the start of the
range.

This is a stop gap until the available refactorings are properly fixed
to be more lenient in general - the current fix is a little odd as eg.
if all of `foo.bar()` is selected, rename will be returned as an
available refactoring for `foo`. Still an improvement over completely
missing cursor based refactorings, however.

Resolves rdar://82060063

tools/swift-refactor/swift-refactor.cpp

@@ -399,9 +399,9 @@ int main(int argc, char *argv[]) {
 
   if (options::Action == RefactoringKind::None) {
     llvm::SmallVector<RefactoringKind, 32> Kinds;
-    bool RangeStartMayNeedRename = false;
-    collectAvailableRefactorings(SF, Range, RangeStartMayNeedRename, Kinds,
-                                 {&PrintDiags});
+    bool CollectRangeStartRefactorings = false;
+    collectAvailableRefactorings(SF, Range, CollectRangeStartRefactorings,
+                                 Kinds, {&PrintDiags});
     llvm::outs() << "Action begins\n";
     for (auto Kind : Kinds) {
       llvm::outs() << getDescriptiveRefactoringKindName(Kind) << "\n";