Chart: Fix layout when show/hide chart components

Summary:
Introduces new layout methods that can be used in combination with
undo commands.

Also fixes:
Use of margins on initial layout
Use of Legend alignment including save/load
Adds undo command for hide/show titles
Adds unit test of new layouting

Todo: Alot!
There are a lot of small and larger problems, eg:
Undo commnds missing for axis manipulation.
Tool info is reset when editing axis title.
Sometime tool docker content is not shown when it is added.
And more...

Tags: #calligra:_3.0

Differential Revision: https://phabricator.kde.org/D4916