Add mode parameter to wrapSource

[juliusknorr]

Allow passing the mode in the wrapSource signature to avoid declaration errors when extending from the class in the Nextcloud encryption code:

https://github.com/nextcloud/server/blob/73c7d0dc8156703341733b9c39c69d05263173da/lib/private/Files/Stream/Encryption.php#L203

Should resole nextcloud/server#26464

[juliusknorr]

@icewind1991 Request for review 😉

[AndyXheli]

@juliushaertl Thank you so much for looking into this what dir should i makes these changes too seems like there are two of the WrapperHandler.php

/var/www/nextcloud/3rdparty/icewind/streams/src/WrapperHandler.php
/var/www/nextcloud/apps/files_external/3rdparty/icewind/streams/src/WrapperHandler.php

So on Nextcloud 20.0.10 i only see
/var/www/nextcloud/apps/files_external/3rdparty/icewind/streams/src/WrapperHandler.php

& on NC 21.0.2 i see both
/var/www/nextcloud/3rdparty/icewind/streams/src/WrapperHandler.php
/var/www/nextcloud/apps/files_external/3rdparty/icewind/streams/src/WrapperHandler.php

[AndyXheli]

I can confirm this dose fix the issue on NC 21.0.2 but not on NC 20.0.10 maybe because NC20.0.10 dose not have both folder structures like NC 21

[AndyXheli]

@icewind1991 are you able to review this :)