[GH-25484] Fix draft removal on post deletion (#25715)

* [GH-25484] Fix draft removal on post deletion

* [GH-25484] Add batch migration to remove orphan drafts

* [GH-25484] Fix tests of migration and draft store

* [GH-25484] Remove translation file changes.

* [GH-25484] Remove translation file changes.

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Co-authored-by: Devin Binnie <52460000+devinbinnie@users.noreply.github.com>
Co-authored-by: Mattermost Build <build@mattermost.com>
Co-authored-by: Harrison Healey <harrisonmhealey@gmail.com>

server/channels/testlib/store.go

@@ -72,6 +72,7 @@ func GetMockStoreForSetupFunctions() *mocks.Store {
 	systemStore.On("GetByName", model.MigrationKeyAddCustomUserGroupsPermissionRestore).Return(&model.System{Name: model.MigrationKeyAddCustomUserGroupsPermissionRestore, Value: "true"}, nil)
 	systemStore.On("GetByName", model.MigrationKeyAddReadChannelContentPermissions).Return(&model.System{Name: model.MigrationKeyAddReadChannelContentPermissions, Value: "true"}, nil)
 	systemStore.On("GetByName", model.MigrationKeyDeleteEmptyDrafts).Return(&model.System{Name: model.MigrationKeyDeleteEmptyDrafts, Value: "true"}, nil)
+	systemStore.On("GetByName", model.MigrationKeyDeleteOrphanDrafts).Return(&model.System{Name: model.MigrationKeyDeleteOrphanDrafts, Value: "true"}, nil)
 	systemStore.On("GetByName", model.MigrationKeyAddIPFilteringPermissions).Return(&model.System{Name: model.MigrationKeyAddIPFilteringPermissions, Value: "true"}, nil)
 	systemStore.On("GetByName", "CustomGroupAdminRoleCreationMigrationComplete").Return(&model.System{Name: model.MigrationKeyAddPlayboosksManageRolesPermissions, Value: "true"}, nil)
 	systemStore.On("GetByName", "products_boards").Return(&model.System{Name: "products_boards", Value: "true"}, nil)