GoogleDriveDownloadRequest, which resolves file id and then downloads it
with GoogleDriveStorage::downloadById().
GoogleDriveStreamFileRequest, which resolves file id and then returns
file stream with GoogleDriveStorage::streamFileById().
This commit also adds GoogleDriveStorage::streamFileById() itself.
A minor GoogleDriveResolveIdRequest fix added.
With these one can download files from Google Drive.
Because of the Google Drive StorageFile now contains yet another field,
`id`. For other storages `id` == `path`, and thus all common Requests
(such as SavesSyncRequest, DownloadFolderRequest, etc) must be using
id() instead of path(). That way these Requests won't cause id resolving
which could be quite slow (when you call it for all files in the folder,
for example).
Now it also creates the "base" ScummVM directory if there is no such
directory yet. This way SavesSyncRequest works fine when no "ScummVM" or
"ScummVM/Saves" folder exist in the Google Drive.
When listing directories, you get a list of StorageFiles, which path()
is actually Google Drive id. Thus, if you list a directory recursively,
you won't be able to determine whether all files are within one
directory or have some hierarchy. I'd fix that as soon as it would be
needed.
GoogleDriveResolveIdRequest gets a lowercase path and searches for the
specified file's id. To do that it lists path's subdirectories one by
one with GoogleDriveListDirectoryByIdRequest.
GoogleDriveListDirectoryByIdRequest gets a Google Drive id and lists
that directory (not recursively).
It has its own GoogleDriveTokenRefresher and knows how to do info().
This commit also contains JSON int -> long long int fix and
CurlJsonRequest '\n' -> ' ' fix.
