Further standardization of toolbar button UI and implementations.

[fschmenger]

As part of #206 and #207 the toolbarbuttons have been standardized, as far as they're a opening a floating or sidebar window. The implementation has been based on 2 base classes ToggleButton and ModuleCard. Other toolbar buttons still use a custom implementation.

This is a memo task to investigate further standardization of the following toolbar buttons:

• ZoomToMaxExtentButton
• Geocoder
• Geolocator
• LocaleSwitcher

Regarding the UI:
On short term we should support a toggle / pressed state for Geocoder. See also #243 for that matter.

Technical Cleanup:
On the long run, we could provide some further abstractions for toolbarbuttons, e.g.

• ActionButton - for ZoomToMaxExtentButton and Geolocator
• MenuButton - for LocaleSwitcher

[fschmenger]

We probably should also revise the folder structure of the wegue code, e.g.

• put all components that are modules (in terms of a having toolbar button) in one folder, e.g. 'src/components/modules'
• put core components in a seperate folder from modules, e.g. 'src/components/core'
• and apparently seperate other code doing more basic stuff, e,g. maps

opened for discussion...