Use Rollbar Apple SDK 3 for native crash collection

Description of the change

This updates the SDK to use the latest Rollbar Apple SDK 3.x which is used for native-level crash collection and some advanced features.

For a full list of improvements included in the new Rollbar Apple SDK, refer to: https://github.com/rollbar/rollbar-apple/releases/tag/3.0.0.

This update also fixes the excessive logging associated with the previous version of the Apple SDK. It also allows us to use the latest platform-specific sqlite3 libraries available to Flutter.

The iOS example project has been updated accordingly to make use of the Rollbar Apple SDK 3.x.

This PR also bumps the SDK version to 1.4.0.

Type of change

[ ] Bug fix (non-breaking change that fixes an issue)
[x] New feature (non-breaking change that adds functionality)
[ ] Breaking change (fix or feature that would cause existing functionality to not work as expected)
[x] Maintenance
[x] New release

Related issues

Fix SC-122326
Fixes https://github.com/rollbar/rollbar-flutter/issues/89

Checklists

Development

[x] Lint rules pass locally
[x] The code changed/added as part of this pull request has been covered with tests
[x] All tests related to the changed code pass in development

Code review

[x] This pull request has a descriptive title and information useful to a reviewer. There may be a screenshot or screencast attached
[x] "Ready for review" label attached to the PR and reviewers assigned
[x] Issue from task tracker has a link to this pull request
[ ] Changes have been reviewed by at least one other engineer

rollbar / rollbar-flutter

Use Rollbar Apple SDK 3 for native crash collection #104