Upgrade to Angular 16

### Issue type

**I'm submitting a ...** (check one with "x")

* [ ] bug report
* [x] feature request
* [ ] question about the decisions made in the repository

### Issue description

**Current behavior:**
I noticed that ngx-admin was upgraded to Angular 15 and not Angular 16 is there any reason that ngx-admin is not using Angular 16 or should we except the upgrade anytime soon? @denStrigo

**Expected behavior:**

**Steps to reproduce:**

**Related code:**

```
insert short code snippets here
```

### Other information:

**npm, node, OS, Browser**
```

```

**Angular, Nebular**
```

```