present_tippr: Add tips to the tree based on taxonomy.
Description
Add tips not on existing tree to the tree via an MRCA node,
if they have congeners. This function will look to see if any tips on the
tree have the same genus as the tip to be added. If there are multiple
members of the genus, the tip will be added subtending the MRCA of all
present congeners. If there is member of the genus, the tip will be added
subtending the parent node of the congener.