Provides debug log which can be written to, but does not affect the host state.

The result of writing to the debug log is implementation specific - it may, for example, be written to a log file, or to stdout etc.

The debug_msg macro supports inline formatting:

```norun extern crate alloc; use tezossmartrollupdebug::debugmsg; use tezossmartrolluphost::runtime::Runtime;

fn logruntime(host: &impl Runtime) { debugmsg!(host, "Simple constant string");

debug_msg!(host, "A format {} with argument {}", "test", 5); } ```

In the simplest case, however, one can also write:

```norun use tezossmartrolluphost::runtime::Runtime;

fn logsimple(host: &impl Runtime) { host.writedebug("A simple constant string"); } ```