chore: wrap standalone runtime with trait

[shuiyisong]

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PR Checklist

Please convert it to a draft if some of the following conditions are not met.

• I have written the necessary rustdoc comments.
• I have added the necessary unit tests and integration tests.
• This PR requires documentation updates.
• API changes are backward compatible.
• Schema or data changes are backward compatible.

[gemini-code-assist]

Code Review

This pull request introduces a StandaloneLeaderServicesController trait to manage the startup and shutdown of services like the procedure manager and WAL provider in standalone mode. It also adds an open_regions_writable_override option to InstanceCreator and DatanodeBuilder, allowing for explicit control over whether regions are opened as writable during startup. Additionally, several creator traits were updated with Send + Sync bounds, and new customization methods were added to InstanceCreator. I have no feedback to provide as there were no review comments.