Solves bugs: #9404 and #79663 This Merge Request changes the Data Source Manager twaindsm.dll alias twain_32.dll to save the data source selected in the selection dialog into the windows registry. This enables applications that do not save the result of the DG_CONTROL/DAT_IDENTITY/MSG_USERSELECT call to be able to choose a data source the same as when using the twain.org DSM. While the twain.org DSM only expects every data source .ds to be responsible for only one data source and thus every call to DG_CONTROL/DAT_IDENTITY/MSG_GET to return the same result, the sane.ds and gphoto2.ds use an extension of the protocol by iterating through cameras/ scanners, always returning a different TW_IDENTITY on every call to DG_CONTROL/DAT_IDENTITY/MSG_GET. For that reason on DG_CONTROL/DAT_IDENTITY/MSG_OPENDS we cannot ask the just opened DS for it's identity as the twain.org DSM does, because it might have more than one Identity. Instead we search the list of data sources retrieved when the DSM was opened for either the identity given by the app or the identity retreived from the registry and give that identity to the MSG_OPENDS call to make the sane.ds open as for the backend we want it to use. This also means that the twaindsm.dll version from twain.org will not be able to manage more than one scanner with sane.ds and one camera with gphoto2.ds as only the wine version of the DSM has the neccessary extension. The twain.org version of the DSM does only save the name of the .DS file choosen by the user to the registry. Since sane.ds and gphoto2.ds can address more than one device, this is not sufficient for us. So the registry entries are not compatible to the ones from the twain.org version. Instead of the filename, we save Manufacturer, ProductFamily and espcially ProductName to the registry under a different registry key. This MR also solves a problem introdoced with commit https://gitlab.winehq.org/wine/wine/-/commit/c7570143bf2305e2292cf5a75abd20c... (by myself) that it was no longer possible to control in DG_CONTROL/DAT_IDENTITY/MSG_OPENDS which of several configured sane data sources are to be opened by sane.ds. A second problem reported in bug report #9404 that crashed the sane.ds when using the user interface with the sane test backend was recently already addressed in commit https://gitlab.winehq.org/wine/wine/-/commit/04449af761451c312f70a71cb62ae7a.... -- https://gitlab.winehq.org/wine/wine/-/merge_requests/9731