There is nothing even remotely close to a white mage healer. Elementalist or Guardian have the most healing options, but at best they have "emergency" AoE heals on long CDs (30-240 seconds) or tiny inconsequential heals that proc off normal damage attacks. I'm not sure there is a single "targeted" heal in the game. They are all either self or area. You can not be a "healer" but every class has options to add some situational healing to their DPS.
I would say guardian has the most heals but I'm not that familiar with elementalists so I might be wrong. But I can tell you that staff guardian has two heals in its skillset from the weapon and the mace has a small heal on its autoattack and a short regenaration buff. Additionally you also have your F2 "Virtue of Resolve" and then you have like three or four utility skills that can heal or at least apply regeneration and on top of that you can have your elite skill "Tome of Courage" which again has two heals, one of which is a full party (five people) heal and a skill that grants regeneration. So yeah lots of heals and I didn't even go into the buffing and battlefield control. Basically I love playing my guardian and enable my party to deal the most damage.
Guild Wars 2 - Aurora Glade EU - Rozalin Allerion (Guardian) If you don't see my name in map chat, I'm not on that map!