[weather] Show optionally temperature next to icon in compact mode

Summary:
Adds the logic for showing an alternative component for the compact
presentation, where the temperature is shown next to the icon with the
weather status (done in flow of layout).

Adds also the matching configuration logic to allow the user to enable that
alternative display.

BUG:302015
BUG:367751
FIXED-IN: 5.12.0

Reviewers: #plasma, broulik

Subscribers: plasma-devel

Tags: #plasma

Differential Revision: https://phabricator.kde.org/D9872