Avoid accessing SYS_TABLESPACES unnecessarily

The view information_schema.innodb_tablespaces_encryption is unnecessarily retrieving the data from the SYS_TABLESPACES table instead of directly fetching it from the fil_system cache. InnoDB always loads all tablespace metadata into memory at startup and never evicts it while the tablespace exists.
Similar unnecessary access could exist elsewhere in InnoDB. We should replace all those. Only the view INFORMATION_SCHEMA.INNODB_SYS_TABLESPACES is intentionally retrieving the data directly from the table.