Fix: Handle 409 "File already exists" conflict during file upload in SyncExtension

[patricioxavier8]

When createFileNew returns a 409 conflict, instead of failing, recover the existing
file using getExistenceFileInFolderByPlainName + getFileMetaByUuid and return it
as a successful FileProviderItem.

[sg-gs]

The 409 indicates that the file name is already in use inside that folder. But the content could be different, because the user could be attempting to replace the file, or is that a different situation in this context @patricioxavier8 ?

[patricioxavier8]

The 409 indicates that the file name is already in use inside that folder. But the content could be different, because the user could be attempting to replace the file, or is that a different situation in this context @patricioxavier8 ?

This is a different scenario. While the validation you mentioned occurs earlier, the user reports that the file is not visible and cannot be deleted because it appears not to exist. This change introduces a fallback to handle those cases and avoid related errors.