* add converters and fix FSTQuery.{h,m} only
* address changes
* a change forget to address
* add a dummy function to make inline-only-library buildable
* implement Firestore DatabaseInfo in C++
* temporary stash changes; blocking on the massive renaming of .m to .mm
* add database_info_test to project
* finish port DatabaseId and fix style, modular fixing DatabaseInfo
* port DatabaseInfo
* remove FSTDatabase{ID,Info} and their tests from project
* fix unit test
* use namespace alias
* use namespace alias, leftover
* address more changes
* refactoring to use raw pointer instead of value for property
* address changes
* remove self->
* fix style
* remove the name suffix Alloc
* fix a bug
* Move all Firestore files to Objective-C++
* Update project file references
* Don't use module imports from Objective-C++
* Use extern "C" for C-accessible globals
* Work around more stringent type checking in Objective-C++
* NSMutableDictionary ivars aren't implicitly casted to NSDictionary
* FSTMaybeDocument callback can't be passed a function that accepts
FSTDocument
* NSComparisonResult can't be multiplied by -1 without casting
* Add a #include <inttypes.h> where needed
* Avoid using C++ keywords as variables
* Remove #if __cplusplus guards
zxu