(DOCSP-33996): Swift: Update progress notification documentation

[dacharyc]

Pull Request Info

Jira ticket: https://jira.mongodb.org/browse/DOCSP-33996

• Manage Sync Sessions: Add a text description with some details. Update code examples.

Reminder Checklist

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

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

Release Notes

• Swift SDK
  • Sync Data/Manage Sync Sessions: Update the documentation for Upload and Download Progress Notifications, which have been updated for compatibility with Flexible Sync.

Review Guidelines

REVIEWING.md

[github-actions[bot]]

Readability for Commit Hash: 8dd9236257dd4eef6107f4746b9d5d36764d9f3e

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

Readability scores for changed documents:

• source/sdk/swift/sync/sync-session: Grade Level: 8.5, Reading Ease: 57.87

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.

[docs-builder-bot]

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

🪵 Logs

• job log: ec6983504eeb0df1291ea9f5ffcb093d0b8e155f