sqlite: Traits: Fix string binding
sqlite: Traits: Fix string binding

rvalue reference to a string were passed to sqlite as a static value,
while its lifetime ends as soon as the function returns.
This also removes support for non-const char*, as we don't expect those.
We now pass const char* (hardcoded strings) and const std::string& using
SQLITE_STATIC, and make sqlite copy temporary buffers (std::string&&)
using SQLITE_TRANSIENT
This fixes a use after free/stack-use-after-scope when passing a
std::string&& to a request helper

chouquette/medialibrary,chouquette/medialibrary,chouquette/medialibrary,chouquette/medialibrary