[REF]: Refactor files-ui directory

src/files-ui/Avatar/Avatar.scss

src/files-ui/Avatar/Avatar.tsx

src/files-ui/Avatar/AvatarProps.ts

src/files-ui/Avatar/index.ts

src/files-ui/Avatar/useAvatarClassName.ts

src/files-ui/Avatar/useAvatarStyle.ts

src/files-ui/DownloadHidden/DownloadHidden.tsx

src/files-ui/DropLayer/components/DropLayer.tsx

src/files-ui/DropLayer/components/DropLayerProps.scss

src/files-ui/DropLayer/components/DropLayerProps.ts

src/files-ui/DropLayer/utils/dropLayerDynamicStyle.ts

.../Dropzone/components/DropzoneButtons/DropzoneButtons.scss

...i/Dropzone/components/DropzoneButtons/DropzoneButtons.tsx

...ropzone/components/DropzoneChildren/DropzoneChildren.scss

...Dropzone/components/DropzoneChildren/DropzoneChildren.tsx

...mponents/DropzoneDisabledLayer/DropzoneDisabledLayer.scss

...omponents/DropzoneDisabledLayer/DropzoneDisabledLayer.tsx

...-ui/Dropzone/components/DropzoneFooter/DropzoneFooter.tsx

...-ui/Dropzone/components/DropzoneHeader/DropzoneHeader.tsx

src/files-ui/Dropzone/components/dropzone/Dropzone.scss