improved
- management of header simplified, no states needed
- no need to use StackViewStates helper
- no need to use internal `d` object as a proxy to pass data between
pages
- StackView used as a base class
- clipping problems fixed (#11285)
- scrolling problems fixed (#11289)
- all flows working from the storybook
- header management simplified
Closes: #11285Closes: #11298
- Renamed main `CommunitiesPortal` folder to `Communities`.
- Created new `layouts` folder.
- Moved layout files from chat to communities.
- Created new `helpers` folder.
- Moved helpers files from chat to communities.
- Moved `controls/community` files from chat to communities `controls`.
- Moved `panels/communities` files from chat to communities `panels`.
- Moved `popups/community` files from chat to communities `popups`.
- Moved `views/community` files from chat to communities `views`.
- Moved `CommunityBanner` file from shared to `Communities/controls`. Only used in communities context.
- Moved `CommunitySettingsView` and `CommunityColumnView` files from chat to communities `views`.
- Moved `PermissionsStore.qml` file to `shared/stores`.
- Updated imports.
- Updated storybook.
Part of #6204
Michał Cieślak
Noelia