unicode support for atoms in asserts is inconsistent

[brigadier]

Describe the bug
unicode support for atoms in asserts is inconsistent. With erl +pc unicode some macroses print atoms in errors correctly, some not. I think it is the issue with the ?? expansion in macroses in general.

To Reproduce
in the erl +pc unicode shell:

-module(test).
-include_lib("stdlib/include/assert.hrl").

-export([test1/0, test2/0, test3/0, test4/0]).

test1() -> 
    ?assertMatch(<<"атом"/utf8>>, atom).

test2() ->     
    ?assertMatch('атом', atom).

test3() ->     
    ?assertEqual('атом', atom).
    
test4() ->
    ?assertMatch({'атом', <<"атом"/utf8>>}, {atom, <<"atom">>}).

Result:

1> test:test1().
** exception error: {assertMatch,[{module,test},
                                  {line,10},
                                  {expression,"atom"},
                                  {pattern,"<< \"атом\" / utf8 >>"},
                                  {value,atom}]}
     in function  test:test1/0 (test.erl, line 10)
2> test:test2().
** exception error: {assertMatch,[{module,test},
                                  {line,13},
                                  {expression,"atom"},
                                  {pattern,"'\\x{430}\\x{442}\\x{43E}\\x{43C}'"},
                                  {value,atom}]}
     in function  test:test2/0 (test.erl, line 13)
3> test:test3().
** exception error: {assertEqual,[{module,test},
                                  {line,16},
                                  {expression,"atom"},
                                  {expected,'атом'},
                                  {value,atom}]}
     in function  test:test3/0 (test.erl, line 16)
4>test:test4().
** exception error: {assertMatch,[{module,test},
                                  {line,19},
                                  {expression,"{ atom , << \"atom\" >> }"},
                                  {pattern,"{ '\\x{430}\\x{442}\\x{43E}\\x{43C}' , << \"атом\" / utf8 >> }"},
                                  {value,{atom,<<"atom">>}}]}
     in function  test:test4/0 (test.erl, line 19)

Expected behavior

2> test:test2().
** exception error: {assertMatch,[{module,test},
                                  {line,13},
                                  {expression,"atom"},
                                  {pattern,"'атом'"},
                                  {value,atom}]}
     in function  test:test2/0 (test.erl, line 13)

Affected versions
at least OTP 27

[garazdawi]

It is macro argument stringification that is causing this.

-module(t).

-export([go/0]).
-define(a(A), ??A).

go() -> {?a(atom),?a('атом')}.

1> c(t).
{ok,t}
2> t:go().
{"atom","'\\x{430}\\x{442}\\x{43E}\\x{43C}'"}

I think this is in order to generate the same result for latin1 and utf8 files. I'll leave figuring out of it is a wanted behaviour or not to others :)