New Homepage layout (#516)

* ENSWBSITES-1114: Build homepage layout
* remove old codes/components not being used anymore
* new grid layout for new homepage
* new assets for homepage
* updated root styling since we only need 2 rows for the grid

* ENSWBSITES-1114: Fix help layout
fix the root grid (should be 2 rows only) as part of the homepage work
updated help page to reflect updated root grid
moved help app header inside main help

* ENSWBSITES-1114: new homepage
updated title tag to be just Ensembl
5 jobs for dev in 4 minutes and 30 seconds (queued for 3 seconds)
Status Job ID Name Coverage
  Test Build Static
passed #492012
Test_N_Build

00:03:30

 
  Build Docker Images
passed #492013
Nginx:Staging

00:00:48

passed #492014
Node:Staging

00:00:52

 
  Deploy
passed #492016
Staging:HL

00:00:06

passed #492015
Staging:HX

00:00:06