Reference design: https://www.figma.com/file/f8b2dHp9LJCMOqYP4mdrPZ/Client%2FChat?node-id=1%3A297
Adds new component `ChannelList` which makes up the sidebar channel
selector of the new chat design. Contains two separate fill flows for
public and private `ChannelItem` child components.
Exposed bindable `SelectorActive` to indicate current state of the "Add
more channels" button. Requires `Bindable<Channel>` from parent
component.
Renames and updates the `TestSceneChannelListItem` to
`TestSceneChannelList` to make use of new component and having both
tests seemed redundant.
Reference design: https://www.figma.com/file/f8b2dHp9LJCMOqYP4mdrPZ/Client%2FChat?node-id=1%3A297
Adds new component `ChatTextBox`.
Exposes `BindableBool` `ShowSearch` to change text input behaviour
between normal and search behaviour.
Adds new component `ChatTextBar`.
Exposes `BindableBool` `ShowSearch` which toggles between showing current
chat channel or search icon.
Additionally binds to child `ChatTextBox` components.
Requires a cached `Bindable<Channel>` instance to be managed by a parent
component.
Adds new component `ChannelControlItem` and it's child components to be
used as the clickable control in the new chat sidebar for joined
channels.
Has public properties `HasUnread` and `MentionCount` to control the
display of the channel having unread messages or mentions of the user.
Channel select/join requests are exposed via `OnRequestSelect` and
`OnRequestLeave` events respectively which should be handled by a parent
component.
Requires a cached `Bindable<Channel>` instance to be managed by a parent
component.
Requires a cached `OveralayColourScheme` instance to be provided by a
parent component.
Adds components `ChannelListing` and `ChannelListing` item with visual
test. Essentially a more simplified version of the existing
`ChannelSelectionOverlay` component.
Correctly implements `IFilterable` behaviour to filter child channel
items. Channel joined state is based on the underlying `Joined` bindable
of the `Channel` class.
Channel join/leave events are exposed via `OnRequestJoin` and
`OnRequestLeave` events which should be handled by parent component.
Requires a cached `OverlayColourScheme` instance to be provided by the
parent overlay component when added.
