fix(credentials): number of matched targets should be updated corretly on notification

[tthvo]

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Related to #1303

Description of the change:

Added an additional API fetch to obtain the up-to-date number of matched targets for a credential since the notification message always returns 0.

There is a small side effect: there is a gap between the time when the notification message is received and the table is updated. I think this is still better than the potential confusion when the number of matched targets is 0 (when it should not be).

Motivation for the change:

See #1303 (comment)