chat: attachment preview: - if there is not already one, a preview is generated for images collection thumbnails, instead of using the full size image. - for images attachment, local path is now used if present, before URL.

<intent-filter>
    <action android:name="android.intent.action.SEND" />
    <category android:name="android.intent.category.DEFAULT" />
    <data android:mimeType="*/*" />
</intent-filter>