Draft: fix: dev: Fix isc_tls_cert_store_t reference counting in TLS context cache
The isc_tlsctx_cache_add() function, when using a 'store' in a new TLS context cache entry, now increases its reference count. As previously, destroying a cache entry is calling isc_tls_cert_store_free() for its 'ca_store' member, which now should be correct for a reused store and not cause a double free.
Closes #4904 (closed)