feat(ocm): expose received webapp metadata - #5853

This PR is part of the cs3org/OCM-STA#20 and cs3org/OCM-STA#48

Summary

• Return the received webapp name on sharedWithMe. WebappMetadataForReceivedShare reads the stored AppName when the received share has exactly one webapp protocol, verbatim with no trim or fallback, and getSharedWithMe hands it to the carrier from refactor(ocm): add graph webapp metadata carrier #5852 for that same share.
• Leave the key out for zero webapp protocols or more than one, rather than guessing which offer applies. A duplicate is logged on the request logger with shareId only, and only appName reaches the API: sharedSecret, appIconHint, and mediaTypes stay on the stored protocol.
• Test through getSharedWithMe against the refactor(ocm): add graph webapp metadata carrier #5852 goldens (CodiMD, key omitted for WebDAV-only, "appName":""), and check that two shares in one response keep their own names.

flowchart TD
    S["received OCM share"] --> W["WebappMetadataForReceivedShare(ctx, share)"]
    W -->|"exactly one webapp protocol"| P["Present, AppName as stored"]
    W -->|"none"| N["nil"]
    W -->|"more than one"| DUP["warn on the request logger, shareId only"]
    DUP --> N
    P --> C["newReceivedShareDriveItem"]
    N --> C
    C -->|"Present"| K["remoteItem @ocm.webApp"]
    C -->|"nil"| U["DriveItem JSON unchanged"]