feat: handle configuration changes from the app

[bm424]

• Adds a handler for messages telling the extension to update its configuration.

Note that VSCode handles calling the language server to update configuration.

See core changes: https://github.com/sourcery-ai/core/pull/3398
See Intellij changes: https://github.com/sourcery-ai/intellij-plugin/pull/148

[sourcery-ai]

PR Type: Enhancement

Summary of PR: This PR introduces a new feature to handle configuration updates from the app by adding a message handler for updating the extension's configuration.

General PR suggestions

• Consider refining the type definition for the value field in the updateConfiguration message to enhance type safety and avoid potential issues.
• Review the naming of the configurationTarget field to ensure it clearly communicates its purpose and consider aligning it with the VS Code API's conventions.
• Implement error handling for the new configuration update functionality to gracefully manage any issues that may arise during the update process.

[Hellebore]

Looks good