Add cookie consent dialog with option to reject tracking

[jvendetti]

In order to submit a BioPortal manuscript proposal to the Nucleic Acids Research Web Server Issue, we're required to implement the following change:

You MUST add a cookie consent form with the option to reject non-necessary analytic cookies

We take this to mean that users should be given the option to reject Google Analytics tracking.

[jonquet]

We have added a cookie banner in ontoportal-lirmm UI's branch. But because the functionality of "desactivating" GA tracking was not implemented, the banner is just an acknowledgement (yes or yes).