[SHARE-777][Feature][HOLD] Add tind.io harvester for AgEcon

[aaxelb]

• Remove the edu.ageconsearch harvester and transformer
• Add io.tind harvester we could use for any source using Tind IR (from their press releases, looks like just AgEcon so far)
• Harvest AgEcon in MODS format

Waiting on a fix on filtering by date range.