Long Menu Title not responsive - Icons disappear

### Issue type

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

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

### Issue description

**Current behavior:**
A ***long*** Menu Item text lets the menu item icon disapear.... So the menu item text is not responsible

**Expected behavior:**
Text schould be ellipsed ("...") at the end or wraped into next line or other lolutions

**Steps to reproduce:**
1. Create MenuItem (NbMenuItem) and set the title to some very long string....

**Related code:**
```
this.menu.push({
title: this.organisation.tenant_name, // this name is flexible so it can be very long....
icon: 'home-outline',
children: this.createPoolChildren(),
});

```

### Other information:

**npm, node, OS, Browser**
```
Node: v14.15.1
OS: Windows (10)
Browser: Chrome
```

**Angular, Nebular**
```

```