RDART-930: Refactor handles

[nielsenko]

Split and refactoring complete.

   wc -l file
       2 ./convert_native.dart
       4 ./ffi.dart
      22 ./query_handle.dart
      22 ./scheduler_handle.dart
      24 ./convert.dart
      24 ./realm_library.dart
      28 ./subscription_handle.dart
      35 ./notification_token_handle.dart
      55 ./map_changes_handle.dart
      70 ./error_handling.dart
      78 ./collection_changes_handle.dart
      80 ./async_open_task_handle.dart
      81 ./subscription_set_handle.dart
      82 ./credentials_handle.dart
      85 ./rooted_handle.dart
      90 ./mutable_subscription_set_handle.dart
      90 ./schema_handle.dart
      93 ./handle_base.dart
     117 ./results_handle.dart
     132 ./set_handle.dart
     142 ./decimal128.dart
     146 ./list_handle.dart
     164 ./session_handle.dart
     172 ./to_native.dart
     191 ./realm_core.dart
     200 ./map_handle.dart
     207 ./object_handle.dart
     268 ./config_handle.dart
     354 ./user_handle.dart
     358 ./from_native.dart
     461 ./realm_handle.dart
     592 ./app_handle.dart
   13407 ./realm_bindings.dart

Fixes: #1479

[coveralls-official]

Pull Request Test Coverage Report for Build 9004258828

Details

• 2028 of 2203 (92.06%) changed or added relevant lines in 47 files are covered.
• 1 unchanged line in 1 file lost coverage.
• Overall coverage increased (+0.1%) to 86.74%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
packages/realm_dart/lib/src/map.dart	21	22	95.45%
packages/realm_dart/lib/src/native/collection_changes_handle.dart	20	21	95.24%
packages/realm_dart/lib/src/native/collection_handle_base.dart	16	17	94.12%
packages/realm_dart/lib/src/native/convert.dart	5	6	83.33%
packages/realm_dart/lib/src/session.dart	10	11	90.91%
packages/realm_dart/lib/src/set.dart	14	15	93.33%
packages/realm_dart/lib/src/credentials.dart	16	18	88.89%
packages/realm_dart/lib/src/native/realm_library.dart	6	8	75.0%
packages/realm_dart/lib/src/native/results_handle.dart	47	49	95.92%
packages/realm_dart/lib/src/realm_object.dart	31	33	93.94%

Files with Coverage Reduction	New Missed Lines	%
packages/realm_dart/lib/src/subscription.dart	1	90.0%

Totals
Change from base Build 9001128643:	0.1%
Covered Lines:	5874
Relevant Lines:	6772

---

💛 - Coveralls