Remove Gargantext.Utils.Seq: if we need it, it should be one directly implemented using the underlying tree

Use thisModule everywhere.

Turns out caches.delete() didn't return a promise.

Also small improvements to Ngrams get (use ngrams get all endpoint).

Changed contacts, rename node, corpus code file name to use input field
where enter confirms the edition.

In Home/Public error was thrown: <div> cannot be nested under <p>.