There is no Lua API for quests or quest granters (Compendium is a manually updated database of game info) and there is no way via Lua to modify the built-in maps (thus the reason for MoorMap) so there is no way to completely implement this. One solution is to use Lunarwater's Compendium and my MoorMap. They are integrated so that if you look up an Item, Quest or Deed in Compendium that has coordinates, you can click on the coordinates and it will open MoorMap with a "ping" at the location of the coordinates. An alternative would be to use Berry's Completionist Tracker (or google) to find quests you've missed and the name of the NPC that grants the quest and find their location on the map or try the built in search function of MoorMap or TerrainMap to locate the NPC. Unfortunately, due to phasing, the NPCs in new areas of the map can change locations based on what portions of quests you have completed so they may not always be at the locations indicated in quest guides or plugins. Neither MoorMap nor TerrainMap have the default annotation data or NPC data for the latest expansion and probably will not for at least another month.
Unfortunately, Compendium is a bit out of date and the Lorebook that used to be used to source much of it's data no longer exists. Since Compendium takes a significant amount of manual labor to update it may not be updated for new content but it is typically still useful for content prior to Rohan.
Berry's Completionist Tracker: