Added some methods to handle plugin activation
JC-1591 Plugins activation improvement
Plugins now activates by checking it's checkbox. Add new methods to PluginController
and TransactionalPluginService.
JC-1591 Formatting and refactoring according last code review

Remove deprecated pluginActivating method, Write test for new pluginActivate method,
Refactor PluginActivatingDto creation in pluginActivate
JC-1591 Now plugin statuses and activation request results provides feedback

Add indicator for plugin statuses, add messages for activation results,
add messages translations for all languages.
JC-1591 Javascript refactoring
JC-1591 Popup fade out animation

Now elements hides and shows by hide() and show() methods, Add
popup fade out animation.

removeClass() and addClass() methods changed width show() and hide()