[NEW] Added tiki application SEO management tool

by this commit i just lay the foundation for a tool that will be over time improved to be more competitive SEO side. here the idea is to be able to centralize all the options and preferences that contribute to the good SEO of our applications. i just put d'abor sitemap and description because i worked recently on it. the more @adrienmaloba and @yan.lupundu will work and add other element to this tool it will be more causto and more stable. however i think some things are not done correctly and moreover it's a commit that depends on other commit already done so i prefer to have your opinion on !2117 (merged) and !2108 (closed) after this one will come at the end