py/lexer: Wrap in parenthesis all f-string arguments passed to format.

This is important for literal tuples, e.g.

    f"{a,b,}, {c}" --> "{}".format((a,b), (c),)

which would otherwise result in either a syntax error or the wrong result.

Fixes issue #9635.

This work was funded through GitHub Sponsors.

Signed-off-by: Jim Mussared <jim.mussared@gmail.com>

tests/basics/string_fstring_debug.py

@@ -21,3 +21,7 @@ print(f"a {x=:08x} b {y} c")
 
 print(f'a {f() + g("foo") + h()=} b')
 print(f'a {f() + g("foo") + h()=:08x} b')
+
+print(f"a {1,=} b")
+print(f"a {x,y,=} b")
+print(f"a {x,1=} b")