DOCSP-37240: Add upgrade page for Flutter SDK v2.0.0 breaking changes

[cbullinger]

Pull Request Info

NOTE: This PR won't include updating the generated snippets. Code examples will be updated and snippets re-generated in DOCSP-37239 as part of test suite version upgrade.

Jira ticket: https://jira.mongodb.org/browse/DOCSP-37240

• Define a Realm Object Schema - Flutter SDK: Add new shared includes note regarding the breaking change, and update .g.dart file extensions to .realm.dart throughout page.
• Upgrade to Flutter SDK v2.0.0: New page for migrating an app from earlier version to v2.0.0 and later.
• Quick Start - Flutter SDK: Update .g.dart file extensions to .realm.dart throughout page.
• Install the Flutter SDK: Add shared includes note to Update Package Version section, and update .g.dart file extensions to .realm.dart throughout page.

Reminder Checklist

Before merging your PR, make sure to check a few things.

• Did you tag pages appropriately?
  • genre
  • meta.keywords
  • meta.description
• Describe your PR's changes in the Release Notes section
• [n/a] Create a Jira ticket for related docs-app-services work, if any

Release Notes

• Flutter SDK
  • Update any .g.dart file extensions to the new .realm.dart extension throughout the SDK documentation.
  • Install: Add note regarding the breaking change to how data model class files generate, and update "Prerequisites" section with updated version and platform requirements.
  • Realm Database/Model Data/Define a Realm Object Schema: Add note regarding the breaking change to how data model class files generate.
  • Upgrade to Flutter SDK v2.0.0: New page detailing the breaking changes to SDK version 2.0.0 and how to upgrade an app from an earlier version.

Review Guidelines

REVIEWING.md

[github-actions]

Readability for Commit Hash: f0fa565

You can see any previous Readability scores (if they exist) by looking
at the comment's history.

Readability scores for changed documents:

• source/sdk/flutter: Grade Level: 9.5, Reading Ease: 50.02
• source/sdk/flutter/install: Grade Level: 5.7, Reading Ease: 70.6
• source/sdk/flutter/upgrade-to-v2: Grade Level: 9.7, Reading Ease: 38.69
• source/sdk/flutter/quick-start: Grade Level: 8.0, Reading Ease: 59.19
• source/sdk/flutter/realm-database/model-data/data-types: Grade Level: 7.9, Reading Ease: 59.6
• source/sdk/flutter/realm-database/model-data/define-realm-object-schema: Grade Level: 8.6, Reading Ease: 57.77

For Grade Level, aim for 8 or below.

For Reading Ease scores, aim for 60 or above:

Score	Difficulty
90-100	Very Easy
80-89	Easy
70-79	Fairly Easy
60-69	Medium
50-59	Fairly Hard
30-49	Hard
0-29	Very Hard

For help improving readability, try Hemingway App.

[nielsenko]

This looks good. Just a few suggestion regarding the actual PR.

However, unrelated to this PR, but spotted while reviewing:

• Minimal flutter and dart version was downgraded to 3.10.0 and 3.0.0 in a previous release.
• The comments about 2.17.x are obsolete, given the 3.10.0 requirement.
• We don't support Windows on Arm, similar to Linux. We should perhaps clarify that.

[lindseymoore]

Some suggestions for adding links, otherwise LGTM! Great work :)

[docs-builder-bot]

✨ Staging URL: https://preview-mongodbmongodb.gatsbyjs.io/realm/master/

🪵 Logs

• job log: 7c134228cd81f48f902d37a77dda6061a8bedd98