[website_seo_blog] Update seo url handling of module website_seo_blog that it will work like in the module website_seo

[rruebner]

Goal

The current seo url implementation in the module website_seo_blog has to be updated that the seo url handling is the same like in the module website_seo. These updates are necessary to remove the fix part "blog-" before the blog and blog post urls. In addition we solve problems with translations.

ToDo

• remove controller funtions seo_blog() and seo_blog_post() and replace them with an overwritten function path_page() from the module website_seo
• remove the fix part "blog-" in all other places