AK: Convert AK::Format formatting helpers to returning ErrorOr<void>

This isn't a complete conversion to ErrorOr<void>, but a good chunk.
The end goal here is to propagate buffer allocation failures to the
caller, and allow the use of TRY() with formatting functions.

Userland/Shell/AST.h

@@ -1512,7 +1512,7 @@ struct Formatter<Shell::AST::Command> : StandardFormatter {
     {
     }
 
-    void format(FormatBuilder&, const Shell::AST::Command& value);
+    ErrorOr<void> format(FormatBuilder&, Shell::AST::Command const& value);
 };
 
 }