[clang-tools-extra] Add support for renaming objc methods, even those with multiple selector pieces (PR #76466)

[Alex Hoppen via cfe-commits]

https://github.com/ahoppen commented:

The outstanding comments from last review are:
- Use `SymbolName` instead of `StringRef`
  - https://github.com/llvm/llvm-project/pull/76466#discussion_r1476409221
  - https://github.com/llvm/llvm-project/pull/76466#discussion_r1476427027
- Don’t re-lex the source file in `collectRenameIdentifierRanges`
  - https://github.com/llvm/llvm-project/pull/76466#discussion_r1476471971
- Use index or AST data to find edits in the current file. AFAICT we do use index-data for the multi-file rename case in `adjustRenameRanges` but I AFAICT no semantic information is used for the current file.
  - https://github.com/llvm/llvm-project/pull/76466/files#r1479029824
  - I think a good test case to add would be
```cpp
// Input
R"cpp(
  @interface Foo
  - (void)performA^ction:(int)action with:(int)value;
  @end
  @implementation Foo
  - (void)performAction:(int)action with:(int)value {
    [self performAction:action with:value];
  }
  @end
  @interface Bar
  - (void)performAction:(int)action with:(int)value;
  @end
  @implementation Bar
  - (void)performAction:(int)action with:(int)value {
  }
  @end
)cpp",
// New name
"performNewAction:by:",
// Expected
R"cpp(
  @interface Foo
  - (void)performNewAction:(int)action by:(int)value;
  @end
  @implementation Foo
  - (void)performNewAction:(int)action by:(int)value {
    [self performNewAction:action by:value];
  }
  @end
  @interface Bar
  - (void)performAction:(int)action with:(int)value;
  @end
  @implementation Bar
  - (void)performAction:(int)action with:(int)value {
  }
)cpp",
```

https://github.com/llvm/llvm-project/pull/76466