Set up legacy SNCL mapping functions

geomagio.edge.sncl implements miniseed sncl mappings.

• Implement geomagio.edge.legacy_sncl with get_scnl and parse_sncl methods.
• Update Miniseed and Edge factories to use these sncl mappings

added In Progress label

marked the checklist item Implement geomagio.edge.legacy_sncl with get_scnl and parse_sncl methods. as completed

marked the checklist item Update Miniseed and Edge factories to use these sncl mappings as completed

mentioned in merge request !96 (merged)

added In Review label and removed In Progress label

mentioned in commit 3095eae3

closed with merge request !96 (merged)

removed In Review label