Added hooks for setting the name of the user and the editor permission

[Peterede]

Allow other apps to supply the name and editing permissions

[alexanderonlyoffice]

Hello @Peterede, thank you for your interest in improving ONLYOFFICE. Could you please describe the aim to be achieved by implementing this feature list. We would ask you to describe the usage scenario.

[Peterede]

In the nextcloud talk app we invite a number of guests to a meeting then share a link to a document with them. We do not want the guests to appear as anonymous, we want to use the name set in the call so this is where the name hook is used. For the editing privileges we do not want guests to be able to edit, only view, so this is where the editable hook is used.

[Peterede]

@alexanderonlyoffice is there anything else needed to merge this pull request into master?

[juliushaertl]

As discussed at the Nextcloud conference we should aim for a unified server UI to set the guest name across different apps. @Peterede Feel free to join the discussion in nextcloud/server#17147

[Peterede]

The hooks implemented in this pull request could be used by the unified server UI to set the guest name. This will then still allow other apps to implement the hooks and extend the behaviour.

[CLAassistant]

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