Update VSA routes to reflect multiple value streams

Summary

As part of !35526 (closed) some value stream analytics routes will be changed, we need to update the requests the FE makes to reflect this, once !35526 (closed) is merged

Affected routes

• /groups/:id/-/analytics/value_stream_analytics/stages => /groups/:id/-/analytics/value_stream_analytics/value_streams/:value_stream_id]/stages for stages of specific value stream ``

Risks

The api requests will stop working if we dont make this change.