Describe the bug
This code:

may invoke PQsendPrepare with a C-style string that's missing a null terminator.

To Reproduce
Execute an SQL statement with a DbConnection, passing an std::string_view that doesn't have a null terminator in order to call this function:

Expected behavior
We add a null terminator if we can't be sure we already have one.

Desktop (please complete the following information):

• OS: NixOS
• Browser: Firefox
• Version: 1.9.10

Additional context
This gist is my code and log output when I initially encountered this; here, the symptom is that multiple SQL statements are incorrectly combined: https://gist.github.com/LordMZTE/9b707013112b870196ae9f95e4a748f5