Analysis: Problem was that tablespaces not encrypted might not have
crypt_data stored on disk.

Fixed by always creating crypt_data to memory cache of the tablespace.

MDEV-8138: strange results from encrypt-and-grep test

Analysis: crypt_data->type is not updated correctly on memory
cache. This caused problem with state tranfer on
encrypted => unencrypted => encrypted.

Fixed by updating memory cache of crypt_data->type correctly based on
current srv_encrypt_tables value to either CRYPT_SCHEME_1 or
CRYPT_SCHEME_UNENCRYPTED.