Fix: cache - base64 value if it contains \0 and the connection is sqlite3

[adamkiss]

Fixes a Cache serialization issue when the cache store is sqlite3 and the cached/serialized object contains any private or protected methods/properties.

Fixes #54082

[taylorotwell]

Would this not break all existing SQLite cache values when it tries to base64 decode?

[adamkiss]

@taylorotwell It wouldn't, because base64 encoded serialisation doesn't include : and ;, which is detected when the read happens: it first checks if the value contains them (= it's raw serialisation) and when it doesn't find any, it decodes the value with base64 first before deserialising.

It does the same thing when using PostgresConnection