Create duplicate detection GitHub Action

[webb-ben]

No description provided.

[adplincinst]

Looks good @webb-ben . What I'm seeing is a new github action in this repo that runs the new yourls-action validate subcommnd to detect duplicate pids in a single file or collection of files within a directory (in gh action case the 'namespaces' directory). I notice though that the PIDS (i.e. urls) are not normalized/standardized and the comparisions are lexical/string based. So I can imagine a scenario (maybe improbable but possibly not) where there is a pid that is http://example.org/mypid1 and another that is http://example.org//mypid1 and another that is http://example.org/MyPID1 . These are all the same URL (I believe caps do not matter per RFC) yet if you do string comparison operation they are distinct.

[webb-ben]

Note the PID service does maintain capital letters in redirects.

See https://geoconnex.us/iow/map (recorded PID)
and https://geoconnex.us/iow/Map (nonexistent PID)