Make app selector a bower package

[adi130987]

• Move app-selector element(from PMP or Dashboard) in this repo.
• Make it configurable so it could be used by other apps. For example add a property like:

menuOptions: {
    type: Array,
    value: []
}

<app-selector menu-options="[[myAppMenuOptions]]">

this.myAppMenuOptions = [
    {
        title: 'Dashboards',
        icon: 'app-selector-icons:dashIcon',
        appBaseUrl: 'dash' // maybe a baseUrl property will be useful too
    },
    {
        title: 'Partnership Management',
        icon: 'app-selector-icons:pmpIcon',
        appBaseUrl: 'pmp'
    },
    // ...
]

• Make it available as a bower package

[adi130987]

@marko911