Retrospective, non-interventional, longitudinal, multi-cohort/parallel group study to assess the safety, tolerability, and efficacy of analgesic therapy with cannabinoids vs. non-cannabinoids in CKD patients with peripheral neuropathic pain/muscle pain depending on the degree of renal impairment (ICD10: N18.1-5) using depersonalized 6-month data from the German Pain e-Registry (CANRELIEF)