add connector list map to check connector info

[ssicard]

Description

Addresses a comment on a previous PR by creating a cache of connectors from which to query information.

Improvements:

• moves context creation into main
• queries https://conduit.io/connectors.json to get a list of all connectors and most recent versions. This removes the need to query github.com
• creates test_helper.go in Validator for use by consuming packages

Fixes # (issue)

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