feature: Add prop role to meta checking

[kiwiroy]

This adds role to the set of meta properties available for checking in tests. It follows a similar pattern to the Test2::Compare::Isa module and leans on Role::Tiny::does_role.

Before:

is $obj, object {
  prop this => Test2::Compare::Custom->new(
    code     => sub { Role::Tiny::does_role($_, 'My::Role') ? 1 : 0 },
    name     => 'ROLE',
    operator => 'does_role()',
  );
}, 'object role composed';

with diagnostics like

# +--------+-----------------------------------------------------+-------------+-------+-----+
# | PATH   | GOT                                                 | OP          | CHECK | LNs |
# +--------+-----------------------------------------------------+-------------+-------+-----+
# | <this> | Mojo::Collection__WITH__My::Roll=ARRAY(0x14e6c03c0) | does_role() | ROLE  | 22  |
# +--------+-----------------------------------------------------+-------------+-------+-----+

After:

is $obj, object {
  prop role => 'My::Role';
}, 'object role composed';

and improved diagnostic

# +--------+-----------------------------------------------------+------+----------+-----+
# | PATH   | GOT                                                 | OP   | CHECK    | LNs |
# +--------+-----------------------------------------------------+------+----------+-----+
# | <role> | Mojo::Collection__WITH__My::Roll=ARRAY(0x11f1e9cd0) | role | My::Role | 23  |
# +--------+-----------------------------------------------------+------+----------+-----+

The Moose roles and Moose::Util::does_role need a little more consideration.