Parse extended method types for protocols

Before:
```objective-c

@protocol BookmarkSource
- (id)bookmarkSourceMenuTitle;
- (void)removeBookmarkSourceMenu:(id)arg1;
- (struct TabPlacementHint)tabPlacementHintForMenu:(id)arg1;
- (void)addBookmarkSourceMenu:(id)arg1 withTabPlacementHint:(const struct TabPlacementHint *)arg2;
- (BOOL)isFilteredFromOtherSources;
- (id)imageForContentItem:(id)arg1;
- (id)titleStringForContentItem:(id)arg1;
- (id)addressStringForContentItem:(id)arg1;
- (id)bookmarkSourceImage;
- (id)bookmarksFromContentItems:(id)arg1;
- (id)bookmarkFromContentItem:(id)arg1;
@end
```

After:
```objective-c
@protocol BookmarkSource
- (NSString *)bookmarkSourceMenuTitle;
- (void)removeBookmarkSourceMenu:(NSMenu *)arg1;
- (struct TabPlacementHint)tabPlacementHintForMenu:(NSMenu *)arg1;
- (void)addBookmarkSourceMenu:(NSMenu *)arg1 withTabPlacementHint:(const struct TabPlacementHint *)arg2;
- (BOOL)isFilteredFromOtherSources;
- (NSImage *)imageForContentItem:(id)arg1;
- (NSString *)titleStringForContentItem:(id)arg1;
- (NSString *)addressStringForContentItem:(id)arg1;
- (NSImage *)bookmarkSourceImage;
- (NSArray *)bookmarksFromContentItems:(NSArray *)arg1;
- (WebBookmark *)bookmarkFromContentItem:(id)arg1;
@end
```