(core) Endpoint to report on the latest version of stable grist-core image

Summary:
New endpoint `/api/version` that returns latest version of stable docker image in format:
```
{"latestVersion":"1.1.12","
  updatedAt":"2024-03-06T06:28:25.752337Z","
  isCritical":false,
 "updateURL":"https://hub.docker.com/r/gristlabs/grist"
}
```

It connects to docker hub API and reads the version from the tag lists endpoint.
Stores telemetry passed from the client such us: current version, deployment type, installationId and others.

Test Plan: Added new test

Reviewers: georgegevoian

Reviewed By: georgegevoian

Differential Revision: https://phab.getgrist.com/D4220

test/server/testUtils.ts

@@ -302,11 +302,26 @@ export async function readFixtureDoc(docName: string) {
 // a class to store a snapshot of environment variables, can be reverted to by
 // calling .restore()
 export class EnvironmentSnapshot {
+
+  public static push() {
+    this._stack.push(new EnvironmentSnapshot());
+  }
+
+  public static pop() {
+    const snapshot = this._stack.pop();
+    if (!snapshot) {
+      throw new Error("EnvironmentSnapshot stack is empty");
+    }
+    snapshot.restore();
+  }
+
+  private static _stack: EnvironmentSnapshot[] = [];
+
   private _oldEnv: NodeJS.ProcessEnv;
+
   public constructor() {
     this._oldEnv = clone(process.env);
   }
-
   // Reset environment variables.
   public restore() {
     Object.assign(process.env, this._oldEnv);