create primary-background-color class

packages/rocketchat-theme/server/colors.less

packages/rocketchat-ui-sidenav/side-nav/accountBox.html

...ges/rocketchat-ui-sidenav/side-nav/createChannelFlex.html

...es/rocketchat-ui-sidenav/side-nav/createCombinedFlex.html

...es/rocketchat-ui-sidenav/side-nav/directMessagesFlex.html

...ages/rocketchat-ui-sidenav/side-nav/listChannelsFlex.html

...ages/rocketchat-ui-sidenav/side-nav/listCombinedFlex.html

...ocketchat-ui-sidenav/side-nav/listDirectMessagesFlex.html

...rocketchat-ui-sidenav/side-nav/listPrivateGroupsFlex.html

...ges/rocketchat-ui-sidenav/side-nav/privateGroupsFlex.html

packages/rocketchat-ui-sidenav/side-nav/sideNav.html

packages/rocketchat-ui-sidenav/side-nav/userStatus.html