Hi,
for DoTs and CC there are three classes that fit best:
Wizard (per-rest caster, individual spell selection via learning and grimoires)
Druid (per-rest caster, automatic spell selection)
Cipher (casts spells with focus which is harvested via weapon damage)
All of them can be good melee performers: Wizards with summoned weapons which are very good, Druids with Spiritshift which is extremely strong while it lasts and Ciphers with normal weapons and their special ability "Soul Whip" which not only transforms damage into focus but also gives you a damage bonus for weapons. They all have nice CC and DoT spells. Cipher's DoT is mostly against single targets but very strong. Wizard and Druid have AoE options for DoTs.
My personal favorite is the Druid. Spiritshift is very potent but has limited duration. So you can play him as a CC/DoT caster mostly but shift as soon as somebody attacks you in melee - and you then shred them to pieces. Spiritshift performance is completely independent from gear - except one special belt, the Wildstrike Belt. This means there's more good gear for the rest of he party since your Druid usually doesn't care as much about it. The best Spiritshift forms are Cat (higher attack speed) or Boar (wounding DoT on every strike). The Cat is better against low DR foes, the Boar is better against high DR foes. Imo it mostly comes down to taste. Boar form is also a little bit more sturdy because it has a little regeneration effect while shifted.
Wizard can have a (much) bigger spell selection, the summoned weapons (mainly Concelhaut's Parasitic Staff and later Citzal's Spirit Lance) have very high base damage and they also have reach, so you can attack from the back row over your front row/tanks which can be an advantage. But Wizards can also deal a lot of ranged weapon damage with Blast + Kalakoth's Minor Blights (another summioned weapon, this time a wand). Blast is an AoE that attaches itself to every wand/rod/scepter attack. It can also transport on-hit/on-crit effects from your weapon - for example prone on critical hit (Overbearing). So in theory everybody in the Blast AoE could be knocked down (if you crit them with the Blast).
Ciphers are my personal least favorite of the trio. Mainly because I consider the focus mechanic as flawed: the action economy isn't great because you have to alternate between weapon damage and casting all the time. And also the transformation of damage into fuel for casts means that the Cipher usually is VERY good in fights with lots of weak foes (which are usually not that hard to win anyways) because dealing lots of damage to weak enemies is easy - but lacks impact in the hardest fights, when dealing a lot of damage is hard and therefore getting focus for spells is difficult and the Cipher can become focus-starved.
But this depends a LOT on the difficulty setting. Ciphers generally perform much better on the lower difficulties up to Veteran where the enemies' defenses aren't so high. So if you plan to play on normal or veteran difficulty you can dismiss what I wrote there. Ciphers are def. the most popular of the three among players - I assume because the mix of weapon damage + spellcasting is entertaining and cool - and because it's fun to annihilate (trash) mobs very quickly. Against bosses the rest of the party can step in then - so it's not a big deal if the Cipher performs a little worse than usual.