Choosing a creation restriction location with a comma in the name is not straightforward

To reproduce:

• create a new space (nested page) with a comma in the name
• create a template provider and try to choose the space created above as a creation restriction location, as follows:
• type a couple of letters from the name
• choose from the suggestions
• save

Upon save, the name of the chosen space will be split in two, on the comma position (see screenshots).

If, however, after having chosen from the suggestions, you edit the value prefilled by the suggestions and you put a backslash ( \ ) just before the comma, the value will be saved properly (not split). It's not clear though that this needs to be done, and a very legitimate question would be what happens if that document indeed contains a backslash and a comma (a lot less probable, though).

This issue is a consequence of the limitations of the multiselect suggest tool, it's not specific to template providers (issue XWIKI-8097 is supposed to be about improving this multiselect suggest).