MINOR: ssl: supports crt-base in crt-store

MINOR: ssl: supports crt-base in crt-store

Add crt-base support for "crt-store". It will be used by 'crt', 'ocsp',
'issuer', 'sctl' load line parameter.

In order to keep compatibility with previous configurations and scripts
for the CLI, a crt-store load line will save its ckch_store using the
absolute crt path with the crt-base as the ckch tree key. This way, a
`show ssl cert` on the CLI will always have the completed path.