Get updated/opened project ID

## Every time, when already existing project saves or opened, or a new project creates, the planner sends the ID of this project to the client

Example of how to get projectId from Roomtodo planner:

<iframe     frameborder="0"     id="iframe"     src="https://example.com/planner/matconfig"> </iframe> <script> window.addEventListener("message", messageListener); function messageListener(e) {     try {         const dataObj = JSON.parse(e.data);         if (dataObj.action === "set_project") { let projectId = data.projectId;         }     } catch (error) {         console.error("Error parse JSON string!");     } } </script>

Also JSON config for client's site has to contains 'enable_set_project': true:

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