Fixes #286 - Implemented UI part of installing an activity or trigger

Implemented the Success case

Implemented the Failure case

Code Cleaning and implemented i18n

Created a new language key for Cancel button text with titleCase

Removed text from the Installer dialog

Removed unused component ts files and less, template files related to it

Reduced the width of the model window as per the designs

Modified server code to stop using the old flogo commands while uninstalling a contribution