Release: v3.6.8

[HoonBaek]

• Improve the index_d_ts
  • Add props types for Channel/component/FileViewer
  • Add props types for ui/FileViewer
  • Import CoreMessageType and SendableMessageType from SendbirdUIKitGlobal
  • Use destructuring import for SendbirdUIKitGlobal
• Add ChangeLog for v3.6.8

## [v3.6.8] (Sep 1 2023)
### Feats:
* Update `ui/FileViewer` to support multiple images
  * Modify the props structure
    ```typescript
    export enum ViewerTypes {
      SINGLE = 'SINGLE',
      MULTI = 'MULTI',
    }
    interface SenderInfo {
      profileUrl: string;
      nickname: string;
    }
    interface FileInfo {
      name: string;
      type: string;
      url: string;
    }
    interface BaseViewer {
      onClose: (e: React.MouseEvent) => void;
    }
    interface SingleFileViewer extends SenderInfo, FileInfo, BaseViewer {
      viewerType?: typeof ViewerTypes.SINGLE;
      isByMe?: boolean;
      disableDelete?: boolean;
      onDelete: (e: React.MouseEvent) => void;
    }
    interface MultiFilesViewer extends SenderInfo, BaseViewer {
      viewerType: typeof ViewerTypes.MULTI;
      fileInfoList: FileInfo[];
      currentIndex: number;
      onClickLeft: () => void;
      onClickRight: () => void;
    }
    export type FileViewerComponentProps = SingleFileViewer | MultiFilesViewer;
    ```
* Export misc. utils
  * `Channel/utils/getMessagePartsInfo`
  * `Channel/utils/compareMessagesForGrouping`
  * `Message/hooks/useDirtyGetMentions`
  * `ui/MessageInput/hooks/usePaste`
* Provide fetchChannelList method via ChannelListContext

### Fixes:
* Apply some props which is related to the `metadata` to the ChannelListQuery
  * Add metadataKey, metadataValues, and metadataStartsWith to the Channel.queries.channelListQuery
  * How to use
    ```javascript
    <Channel or ChannelProvider
      queries={{
        channelListQuery: {
          metadataKey: 'isMatching',
          metadataValues: ['true'],
        }
      }}
    />
    ```
* Improve types of `ui/FileViewer` and `Channel/component/FileViewer`
  * Add some props that have been missed
* Fix `<ImageRenderer />` not converting number to pixel string
* Modify the yypes on useChannelContext & useThreadContext
  * `useChannelContext.setQuoteMessage` should accept `UserMessage | FileMessage`
  * `useThreadContext.sendMessage` should be `string`

[chohongm]

LGTM!

[AhyoungRyu]

👍