[!!!][BUGFIX] Ensure fallback to default templates is always set

To ensure that blog templates can be overwritten
partly the default is now always pointing to the
templates within the blog extension.

Migration is only nessesary if you have previously
overwritten the templates within your setup and used
the key "1" as pointer for your templates.

```
plugin.tx_blog {
    view {
        templateRootPaths {
            0 = EXT:blog/Resources/Private/Templates/
            1 = {$plugin.tx_blog.view.templateRootPaths}
        }
        partialRootPaths {
            0 = EXT:blog/Resources/Private/Partials/
            1 = {$plugin.tx_blog.view.partialRootPaths}
        }
        layoutRootPaths {
            0 = EXT:blog/Resources/Private/Layouts/
            1 = {$plugin.tx_blog.view.layoutRootPaths}
        }
        emails {
            templateRootPaths {
                0 = EXT:blog/Resources/Private/Mails/Templates/
                1 = {$plugin.tx_blog.view.emails.templateRootPaths}
            }
            partialRootPaths {
                0 = EXT:blog/Resources/Private/Mails/Partials/
                1 = {$plugin.tx_blog.view.emails.partialRootPaths}
            }
            layoutRootPaths {
                0 = EXT:blog/Resources/Private/Mails/Layouts/
                1 = {$plugin.tx_blog.view.emails.layoutRootPaths}
            }
        }
    }
}
```

Configuration/TypoScript/Static/setup.typoscript

@@ -12,16 +12,34 @@ plugin.tx_blog {
         storagePid = {$plugin.tx_blog.settings.storagePid}
     }
     view {
-        templateRootPaths.0 = {$plugin.tx_blog.view.templateRootPaths}
-        partialRootPaths.0 = {$plugin.tx_blog.view.partialRootPaths}
-        layoutRootPaths.0 = {$plugin.tx_blog.view.layoutRootPaths}
+        templateRootPaths {
+            0 = EXT:blog/Resources/Private/Templates/
+            1 = {$plugin.tx_blog.view.templateRootPaths}
+        }
+        partialRootPaths {
+            0 = EXT:blog/Resources/Private/Partials/
+            1 = {$plugin.tx_blog.view.partialRootPaths}
+        }
+        layoutRootPaths {
+            0 = EXT:blog/Resources/Private/Layouts/
+            1 = {$plugin.tx_blog.view.layoutRootPaths}
+        }
         widget.TYPO3\CMS\Fluid\ViewHelpers\Widget\PaginateViewHelper.templateRootPath = EXT:blog/Resources/Private/Templates
 
         # Emails
         emails {
-            templateRootPaths.0 = {$plugin.tx_blog.view.emails.templateRootPaths}
-            partialRootPaths.0 = {$plugin.tx_blog.view.emails.partialRootPaths}
-            layoutRootPaths.0 = {$plugin.tx_blog.view.emails.layoutRootPaths}
+            templateRootPaths {
+                0 = EXT:blog/Resources/Private/Mails/Templates/
+                1 = {$plugin.tx_blog.view.emails.templateRootPaths}
+            }
+            partialRootPaths {
+                0 = EXT:blog/Resources/Private/Mails/Partials/
+                1 = {$plugin.tx_blog.view.emails.partialRootPaths}
+            }
+            layoutRootPaths {
+                0 = EXT:blog/Resources/Private/Mails/Layouts/
+                1 = {$plugin.tx_blog.view.emails.layoutRootPaths}
+            }
         }
     }
     settings {