Expose Structured Mock Migrations (#1600)

* added mock structured

* builds

* re-export escape

* move show

* started adding structured representation to AddTable

* make AddTable structured

* remove unneeded lines

* ran fourmolu

* added changelog

* Ran fourmolu again

* manually add restyle

* fix version @SInCE, add newtype to SafeToRemove

* updated constructors to better names

* remove unneeded partition

* move to NEL for reference

* fourmolu

* move structured migration to internal

* fourmolu

* remove unused

* Removed redundant code from mock migration

* tests compile

* Fourmolu

* fixed typo

* update type

* fourmolu

* update changelog

* derived eq

* update cabal version

---------

Co-authored-by: Kuba Karpierz <karpierz@MacBook-Pro-51.local>

Author: mercury-kuba

persistent-postgresql/ChangeLog.md

@@ -1,7 +1,11 @@
 # Changelog for persistent-postgresql
 
-## Unreleased
+## 2.13.7.0
 
+* [#1600](https://github.com/yesodweb/persistent/pull/1600)
+    * Add `migrateStructured` to `Database.Persist.Postgresql.Internal`.
+      This allows you to access a structured representation of the proposed migrations
+      for use in your application.
 * [#1547](https://github.com/yesodweb/persistent/pull/1547)
     * Bump `libpq` bounds