Update V2 with bootstrap 4.5.x, bug corrected on horizontal filters, upgrade django version and more

[pulse-mind]

In this pull request I've done a lot of improvements :

• upgrade to bootstrap 4.5.x (with badges)
• upgrade to django 2.2.x
• upgrade node dependencies
• upgrade gulp script

close #768 close #769 close #628 close #746 close #704 close #657 close #624 Work for #475

Please accept this pull request