(DOCSP-35302): C++: Add new sync control methods

[dacharyc]

Pull Request Info

Jira ticket: https://jira.mongodb.org/browse/DOCSP-35302

• Quick Start: Regenerate the "Open a Synced Realm" example without the sync session initialization and method call.
• Sync/Manage Sync Sessions: Add new sync control methods for C++ v1.0.0.

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
• Create a Jira ticket for related docs-app-services work, if any

Release Notes

• C++ SDK
  • Quick Start: Remove sync session initialization and method call from the "Open a Synced Realm" example.
  • Sync/Manage Sync Sessions: Add new sync control methods for C++ v1.0.0.

Review Guidelines

REVIEWING.md

[github-actions]

Readability for Commit Hash: a51b724

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

Readability scores for changed documents:

• source/sdk/cpp/quick-start: Grade Level: 7.0, Reading Ease: 67.25
• source/sdk/cpp/sync/manage-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.

[cbullinger]

Overall lgtm!

[docs-builder-bot]

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

🪵 Logs

• job log: 3c316d335b110512a14b2edee4a148bb7973d858