pericarp and its parts

[planteome-user]

These were originally dealt with in the "new is_a parents": https://github.com/Planteome/plant-ontology/issues/149

Existing definitions: PO:0009084 pericarp: A wall of a fruit, developed from the ovary or carpel wall. >p of p tissue

PO:0009085 epicarp: A portion of plant tissue that is the outer layer of a pericarp. >p of p tissue

PO:0009086 endocarp: A portion of plant tissue that is the innermost differentiated layer of a pericarp. >p of p tissue

PO:0009087 mesocarp: A portion of plant tissue that is the middle layer of a pericarp. >p of p tissue

exocarp PO:0009085: A portion of plant tissue that is the outer layer of a pericarp.

Need to add synonym: fruit epidermis

Reported by: cooperl09

Original Ticket: obo/plant-ontology-po-term-requests/511