Summary:
Make the plasmoid content transparent
Include battery info in header
Only show remotekeyboard input if available
Make header always centered

before:
{F3820966}

after:
{F3820965}

Reviewers: #kde_connect, apol

Reviewed By: #kde_connect, apol

Subscribers: jeanv, albertvaka, apol, #kde_connect

Tags: #kde_connect

Differential Revision: https://phabricator.kde.org/D6943