[13.x] put _type before _id for polymorphic table columns

[browner12]

This commit orders all of our polymorphic table columns with *_type first and *_id second.

This matches how the columns are actually generated by the migration helper methods:

$table->nullableulidMorphs('nullableulidMorphs');
$table->ulidMorphs('ulidMorphs');
$table->uuidmorphs('uuidmorphs');
$table->nullableUuidMorphs('nullableUuidMorphs');
$table->morphs('morphs');
$table->nullableMorphs('nullableMorphs');

results in:

• nullableulidMorphs_type
• nullableulidMorphs_id
• ulidMorphs_type
• ulidMorphs_id
• uuidmorphs_type
• uuidmorphs_id
• nullableUuidMorphs_type
• nullableUuidMorphs_id
• morphs_type
• morphs_id
• nullableMorphs_type
• nullableMorphs_id

This will help encourage consistency between morph columns generated by the helpers, and any the user may manually define.

I think it also makes sense from a readability standpoint; Comment 5, Tag 17, etc.