Expand annotations to cover all generated methods

Expand annotations to cover all generated methods

This is needed for the next commit, as we need a reliable way to tell gened
methods apart from everything else. Given we will be taking the hit of adding
the attributes, just go ahead and annotate *everything*, to be done with all
auto-generated subs once and for all.

This also solves @vanstyn's long-time gripe of not being able to tell where
in a random schema one has declared m2m "relationships" (a typical customer is
*very* unlikely to be using DBIC::IntrospectableM2M)

As of this commit a typical Result can be introspected for m2m as follows:

~$ perl -Ilib -It/lib -MDBICTest -MPackage::Stash -e '

  my $meths = Package::Stash->new("DBICTest::Schema::Artwork")
                             ->get_all_symbols("CODE");

  for my $m (sort keys %$meths ) {
    print "$m\n" if grep {
      $_ =~ /^DBIC_method_is_m2m_sugar/
    } attributes::get($meths->{$m});
  }
'

While the more involved "complete method map" looks as follows:

~$ perl -Ilib -It/lib -MDBICTest -MPackage::Stash -e '

  my $meths = Package::Stash->new("DBICTest::Schema::CD")
                             ->get_all_symbols("CODE");

  for my $m (sort keys %$meths ) {
    if ( my @attrs = attributes::get($meths->{$m}) ) {
      print "\n$m\n";
      print "  $_\n" for @attrs;
    }
  }
'