Fix dagre error with child named "id"

[gavin-ts]

Summary

Create object mapper for dagre and create safe integer ids for dagre to use during layout.

Details

• fixes dagre: barfs on "id" child nodes #1605
• adds dagre_child_id_id test
• dagre has problems with certain strings such asx.id as an id, so we just give it nice integers to use
• dagre order now based on g.Objects order instead of ID strings (dagre would put id: 1 before id: 2 even if you defined id: 2 first see ovals/people tests)
  • Note: I think this was from js numbers and object key iteration which always iterates ints first (in-order):

test now successful

e2ereport