Executes a monitor command
This function wraps the `VALGRIND_MONITOR_COMMAND` macro. It sends the provided
string directly to the Valgrind core, which parses and executes it as if it were
entered into the Valgrind monitor (e.g., via `vgdb`).
# Output
If a GDB instance is connected to Valgrind via `vgdb`, the output is sent
according to the `vgdb` output mode. If no connection exists, the output goes to
the Valgrind log.
# Technical Note
Command syntax is verified at runtime. Where a specific client request exists
(e.g., [`memcheck::leak_check`](crate::memcheck::leak_check)), prefer that
function over this generic wrapper to enforce compile-time argument checking.
# Errors
- [`CommandNotFound`](CommandNotFound) – The command was not recognized.
## Note
Requires Valgrind **3.6** or higher.