studies/{studyDbId} produces too much output; revision stdd2tbl() needed

[mverouden]

The list study details call (/studies/{studyDbId}) works for simple cases, e.g.
con <- ba_db()$sweetpotatobase; ba_studies_details(con = con, studyDbId = "182)

When the case gets more complicated, the output is horrible, e.g.
con <- ba_db()$testserver; ba_studies_details(con = con, studyDbId = "1001")

The problem is caused by the stdd2tbl() function, which is in serious need of revision. Suggested strategy would be to use a similar approach as in the trld2tbl2() function.