Improve `puppetserver ca list` speed when querying for requests

Puppetserver CA CLI is currently very slow when querying for CSRs (or requested state).  As of right now, when a user want to list all of the requests pending through using puppetserver ca list, the CLI would get all of the certificates and CSRs then filter to the user's queried state.  The impact on performance is noticeable when the user has a lot of signed or revoked certificates. 

Outcome

Update the CLI (more specifically the list action) to only look for CSRs when the state being queried is requested. The performance when using puppetserver ca list should be faster than puppetserver ca list --all when there exists a lot of signed or revoked certificates.