REORG: ssl: move the ckch_store related functions to src/ssl_ckch.c

REORG: ssl: move the ckch_store related functions to src/ssl_ckch.c

Move the cert_key_and_chain functions:

int ssl_sock_load_files_into_ckch(const char *path, struct cert_key_and_chain *ckch, char **err);
int ssl_sock_load_pem_into_ckch(const char *path, char *buf, struct cert_key_and_chain *ckch , char **err);
void ssl_sock_free_cert_key_and_chain_contents(struct cert_key_and_chain *ckch);

int ssl_sock_load_key_into_ckch(const char *path, char *buf, struct cert_key_and_chain *ckch , char **err);
int ssl_sock_load_ocsp_response_from_file(const char *ocsp_path, char *buf, struct cert_key_and_chain *ckch, char **err);
int ssl_sock_load_sctl_from_file(const char *sctl_path, char *buf, struct cert_key_and_chain *ckch, char **err);
int ssl_sock_load_issuer_file_into_ckch(const char *path, char *buf, struct cert_key_and_chain *ckch, char **err);

And the utility ckch_store functions:

void ckch_store_free(struct ckch_store *store)
struct ckch_store *ckch_store_new(const char *filename, int nmemb)
struct ckch_store *ckchs_dup(const struct ckch_store *src)
ckch_store *ckchs_lookup(char *path)
ckch_store *ckchs_load_cert_file(char *path, int multi, char **err)