Import Firestore release 1.10.0 from GitHub (Firebase 6.16.0, M63).

The manual changes are:
- remove stale reference to `util/status_testing.h` from `core/BUILD` under `third_party/`;
- rename references to `api::Query::Limit` to `api::Query::LimitToFirst`;
- make the destructor of `util::Filesystem` virtual to prevent compiler warning (Linux is compiled with `-Werror`);
- update testapp podfiles and Unity build files to require the FirebaseFirestore 1.10.0 CocoaPod.

Note: M62 is deliberately skipped/rolled into this import.

Some transaction-related tests are failing until cr/292025113 is submitted (e.g., see https://sponge.corp.google.com/target?id=e30aaf69-d309-402c-accd-3a9bc7318bf9&target=//firebase/firestore/client/cpp:transaction_test_emulator&searchFor=user:varconst&show=FAILED%2CPENDING&sortBy=STATUS).

Copybara-generated description follows:

Import of Firestore from GitHub.

  - c7e0e125e43c695a0f4178f68fc977727f6a2f32 Update versions for Release 6.16.0 by Maksym Malyhin <[email protected]>
  - ecb26bf43822381d3116662c137bef26040b74bc Migrate LevelDB data out of ~/Documents (#4609) by Gil <[email protected]>
  - 9313d61a2131d919ffc58186988b3ae7e91d68ea Add verify support (#4658) by Brian Chen <[email protected]>
  - bdd111ff28e58c8036d0e3aa3c771447660c5939 Put coments directly above enum definition (#4679) by Gil <[email protected]>
  - 51e17ac8c5e5c29d3b73b4668aa117ca8eb11b68 Rename QueryData|Cache to TargetData|Cache (#4670) by wu-hui <[email protected]>
  - 2328d1f365982bccd37c92656f41f177814ea1c2 Merging the 6.15.0 release into master (#4682) by Sam Edson <[email protected]>
  - ff21f1ecb35d63027642a6c0ed74d8851bf506d4 Make a Filesystem class that can be subclassed for testin... by Gil <[email protected]>
  - 423a62f874debcf20e08610dd40f217fefe1474f Enable Index-Free queries (#4618) by Sebastian Schmidt <[email protected]>
  - 6cc1a449ea81db923e57703db6f538be240341de Clean up Objective-C interop and other dead code (#4601) by Gil <[email protected]>
  - fe822f4fab3321953c3e86d35420d7d152ae17e4 Update CHANGELOG for Firestore v1.9.0 (#4626) by Gil <[email protected]>
  - 14e28121e2c83127eedce73f3d3983bbb1ce7182 Release LimitToLast (#4616) by wu-hui <[email protected]>
  - 9a4f4e73c7b6d8b8ba360168ffe6764617d841a4 Miscellaneous fixes (#4584) by Gil <[email protected]>
  - d261cdeb9bec45317c2d5086336e3a3b5f33e651 Finish Index-Free queries (still disabled) (#4484) by Sebastian Schmidt <[email protected]>
  - df3989b8a296b109256566eff64c79a12a5a6bb7 Fix lint warnings spotted by google3's linter (#4538) by Gil <[email protected]>
  - c17e1dfad8255305624d25eb120e0f6445243f78 Permanently fix formatting presubmit warnings in google3 ... by Gil <[email protected]>

PiperOrigin-RevId: 292221182

Author: var-const

firestore/src/ios/query_ios.cc

@@ -50,7 +50,7 @@ Query QueryInternal::OrderBy(const FieldPath& field_path,
 }
 
 Query QueryInternal::Limit(int32_t limit) {
-  return MakePublic(query_.Limit(limit));
+  return MakePublic(query_.LimitToFirst(limit));
 }
 
 Future<QuerySnapshot> QueryInternal::Get(Source source) {