make namespace usage consistent with double underscore

[holic]

We're now using a double underscore delimiter for namespaced function signatures ({namespace}__{functionName}) and may need to update other areas to be consistent with this change:

• SQL table names/schemas
• MUD config output and TS types
• human-readable resource IDs (currently uses colon as a delimiter)

[holic]

I think this is good enough. The rest will come with the config refactor (#1668)