FR: Add ability to share multiple portals with maps as a multistop route

[RickyGrassmuck]

Will update description with more details when I get home, just didn't want to forgot to look into this.

It would be great to take a list of bookmarked portals and generate a multi stop route in maps from that list. Not a trivial change but I plan to look into it more tonight and over the weekend.

[DanielOndiordna]

Hi there. My community plugin can create Maps routes with multiple waypoints. Not from Bookmarks. My plugin has it's own portal marker technique.
https://softspot.nl/ingress/plugindetails/iitc-plugin-maps-route-planner