Important changes:
* Refactored QtRequests to accept parameters for `GET` operations
* Infer response data type from content-type header
* Support caching to disk, a manager with this set prefers the cache
* Support multiple handlers for a single request (unused, possibly pointeless)
* Subclass `ShopImageWidget` for all widgets used in the shop
* Request a resized image instead of the original one
* Fix the search and browse functions
* Remove the annoying stacked widget, instead create a double layout in
the container and place a label in that to hold the placeholder message.
* Implement the scroll area as a custom widget. This custom widget installs
an event filter on the container to adjust the scrollarea size when the
container size changes.
QToolButton is not really designed to be used in the way we did and since
QPushButton supports having a menu attached to, we can replace tool buttons
in most cases.
* Fix the presentation of the TabButtonWidget by updating RareStyle's css
* Reduce the size of the top tab bar to save vertical space.
* Remove infoLabel property
Do not create multiple library views and remove the ability to switch
between them on the fly. Add an option in settings to select the preferred
view. The view will be used the next time Rare is started.
* Add an option to select the library view mode.
This will allow us to instantiate only one library view at startup,
reducing time and complexity of the process.
* Remove base Qt translations from repo, load translations from Qt itself
* Prefix translation `qm` files with `rare_`.
* Rename `translation_source.ts` to simply `source.ts`
* If the selected language matches the system local, remove the option from the configuration.
* Instead of using legendary's locale as fallback, use system't locale
as default.
* Do not hardcode language names and countries but use QLocale on
the translation filenames.