Ingest for SNOMED-ICD10CM mappings

## Overview
There are some [ICD10CM::SNOMED mappings maintained by UMLS](https://www.nlm.nih.gov/research/umls/mapping_projects/snomedct_to_icd10cm.html). We want to essentially get these into SSSOM.

## Sub-tasks
- [ ] 1. Simple mappings
- [ ] 2. Complex mappings

## Related
- #58
- #42
Clone of:
- https://github.com/mapping-commons/disease-mappings/issues/8