select agents by more things

[dustymc]

Is your feature request related to a problem? Please describe.

In anticipation of #6813 / #7318 - a future agent may have no unique characteristics, yet it may be necessary to choose one of them. There may be 300,000 or so 张玮 (even if we completely avoid duplicates!), we need some mechanism to specify THAT PARTICULAR Wei Zhang from text-based tools (eg bulkloaders).

Describe what you're trying to accomplish

^

Describe the solution you'd like

allow getAgentID() to deal with

• https://arctos.database.museum/agent/21334678 (generated identifier)
• attributes (include supplied identifiers such as ORCID)

Describe alternatives you've considered

No thanks, they're all ugly.

Additional context

https://github.com/ArctosDB/arctos/issues?q=+label%3AFunction-Agents+

Priority

Need this in place after attributes, before dropping constraints.

Shouldn't change any existing functionality, going direct.