A small Data Pack I made which includes every new variant of villagers up to 19w08b! If any more are added, I'll add them in the future. It's based off the wall that Xisumavoid made, but ( at least at the time I made this) there isn't a download link. Huge thanks to him though for the concept.

Villagers in 1.14 come with a Biome, a Profession, and a Level. Each wall is classified by level and direction the villagers are facing, you always want to spawn the wall opposite to the direction you are facing, if you don't know what direction you are facing, the f3 menu will tell you.

To spawn in a wall, simply face a direction and use the command:
  /function ecvillagers:all/lvl_(1-5)/(Direction Opposite you are facing.)

or for Zombie Villagers:
  /function ecvillagers:all_z/lvl_(1-5)/(Direction Opposite you are facing.)

And that's really it! Its more of just a visual showcase if anything, but it at least means you don't have to spawn all the villagers by hand. Each Villagers is named according to biome and profession, and they should each have trades. If there is any concerns or problems, feel free to comment and i'll get to them when I check back.

Have a good day!