Federating editing fails when the document has & in its name

[elzody]

Describe the bug
When using federated editing on a document located in a shared folder, and the document has a & symbol in its name, the editing fails. One thing to note is that, if the shared file is not located in some subfolder, federated editing works file, even with the symbol in its name. My belief is that it is due to the file_path parameter being passed on the URL to get the token when the document is in a subfolder.

To Reproduce
Steps to reproduce the behavior:

1. Have two Nextcloud instances with federation set up appropriately
2. As one user on one instance, share a folder with some documents inside, with a & in their names
3. As another user on the other instance, access the shared folder and try to open one of the documents
4. You get an error "Failed to open the requested file"

Expected behavior
The document will open for editing, regardless of if & is in its file name.