AK+Everywhere: Do not implicitly copy variables in TRY macros

For example, consider cases where we want to propagate errors only in
specific instances:

    auto result = read_data(); // something like ErrorOr<ByteBuffer>
    if (result.is_error() && result.error().code() != EINTR)
        continue;
    auto bytes = TRY(result);

The TRY invocation will currently copy the byte buffer when the
expression (in this case, just a local variable) is stored into
_temporary_result.

This patch binds the expression to a reference to prevent such copies.
In less trival invocations (such as TRY(some_function()), this will
incur only temporary lifetime extensions, i.e. no functional change.

Userland/Libraries/LibVideo/DecoderError.h

@@ -79,7 +79,7 @@ private:
 
 #define DECODER_TRY(category, expression)                                                  \
     ({                                                                                     \
-        auto _result = ((expression));                                                     \
+        auto&& _result = ((expression));                                                   \
         if (_result.is_error()) [[unlikely]] {                                             \
             auto _error_string = _result.release_error().string_literal();                 \
             return DecoderError::from_source_location(                                     \