User must select parent before meiosis starts

When we move to meiosis animation, we check if user has selected
a first parent. If they have not, we wait until they do.

User selects parent by clicking either on drake image or on
chromosome image.

[#69270664]
Show meiosis parent-selection tutorial

Change order of meiosis description tutorial;
Hide breed button tutorial on click

Make first meiosis tutorial point to whichever parent
the user selected.

[#69270664]