Support for Angular 16

### Issue type

**I'm submitting a ...**

* [ ] bug report
* [x] feature request

### Issue description

**Current behavior:**

Nebular 11 does not support Angular 16, it expects Angular 15 as a dependency. When used with Angular 16, `npm` complains about unresolved dependencies.

**Expected behavior:**

Nebular should work out of the box with Angular 16.

**Steps to reproduce:**

Basically follow the installation instructions of Nebular: https://akveo.github.io/nebular/docs/guides/install-nebular#install-nebular

`npm install -g @angular/cli@16`
`ng new --defaults angular-nebular-test`
`cd angular-nebular-test`
`ng add @nebular/theme`

```
ℹ Using package manager: npm
⚠ Unable to find compatible package. Using 'latest' tag.
⚠ Package has unmet peer dependencies. Adding the package may not succeed.

The package @nebular/theme@11.0.0 will be installed and executed.
Would you like to proceed? Yes
npm ERR! code ERESOLVE
npm ERR! ERESOLVE unable to resolve dependency tree
npm ERR!
npm ERR! While resolving: angular-nebular-test2@0.0.0
npm ERR! Found: @angular/animations@16.0.5
npm ERR! node_modules/@angular/animations
npm ERR! @angular/animations@"^16.0.0" from the root project
npm ERR!
npm ERR! Could not resolve dependency:
npm ERR! peer @angular/animations@"^15.0.0" from @nebular/theme@11.0.0
npm ERR! node_modules/@nebular/theme
npm ERR! @nebular/theme@"11.0.0" from the root project
npm ERR!
npm ERR! Fix the upstream dependency conflict, or retry
npm ERR! this command with --force, or --legacy-peer-deps
npm ERR! to accept an incorrect (and potentially broken) dependency resolution.
```

### Other information:

**npm, node, OS, Browser**

Node `v16.15.1`
npm: `8.11.0`

**Angular, Nebular**

Angular: `16.0.0`
Nebular: `11.0.0`