fix(notifications): correctly append query parameters

[andrewazores]

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See #1544

Description of the change:

When the request already contains query parameters, for example when originating from the Archives view where a ?tab=foo query parameter is used for routing to the specific tabbed subview, the previous logic would incorrectly build a query string like ?tab=foo?ns=namespace&name=cryostat. Note the doubled-up ?.